research activities in 2007 - CSEM

centre suisse d’électronique
et de microtechnique
Scientific and
Technical Report 2007

CSEM
Centre Suisse d’Electronique
et de Microtechnique SA
CSEM is a privately held research and development company
active in:
•
•
•
•
Applied Research
Product Development
Prototype and Low-volume Production
Technology Consulting
Its main fields of activity are micro- and nanotechnologies,
microelectronics, systems engineering, microrobotics,
photonics, information and communication technologies.
In providing its high-tech know-how and technological
expertise, CSEM strives to anticipate the future needs of
different markets in terms of new technologies and offers
its services to industrial customers. It also develops its own
commercial activities – either together with existing companies
or through the creation of spin-offs and start-up companies –
and actively contributes to developing Switzerland as a hightech
industrial location.
In July 2007, a major of the Neuchâtel Observatory was
integrated into CSEM to continue to develop space-related
technologies. CSEM microsystems and miniaturization
competences will be a clear advantage in terms of new
developments in this area. Furthermore, CSEM opened in
August a new research center in Landquart aimed at developing
new technologies and competences in nanomedicine.
CSEM operates from its headquarters in Neuchatel and also
has centers in Zurich, in Landquart and at Alpnach, near
Lucerne. It is also internationally active, in many European
countries as well as overseas. CSEM is pursuing its
geographical expansion strategy on a national as well as an
international level. This growth offers medium- and long-term
stability, essential in an R&D environment.
At the end of 2007, the total number of employees at CSEM
was 348 of which 26 were Ph.D candidates. Additionally,
approximately 500 people are employed by the 26 spin-offs
and start-ups created to date. In 2007, CSEM earned 58.1
million Swiss francs and presented a positive balance sheet.

CONTENTS
PREFACE 5
RESEARCH ACTIVITIES IN 2007 7
ThruCOS – From Biosensor Chip to Robust Analytical
System 9
Counterfeit – Machine Readable Covert Security
Feature 10
MicroMec – Microtechnology for Silicon Compliant
Structures 11
ArrayFM – An Atomic Force Microscope Using
2-Dimensional Probe Arrays 12
MicroStruc – Integrated Optical Polymer Platform,
Low Cost Assembly and Packaging 13
Encoder – Nanometric Optical Absolute Position
Encoder 14
RISE – The Rich Sensing Concept 15
PackTime – Zero-Level Packaging of Silicon
Time-base 16
TissueOptics – Portable SpO2 Monitor: a Fast
Response Approach Tested in an Altitude Chamber 18
TUGON – Compact MEMS-based Spectrometers for
Infra-Red Spectroscopy 19
Solar Islands – A Novel Approach to Cost Efficient
Solar Power Plants 21
MICROELECTRONICS 23
Data Fusion for Wireless Distributed Tracking Systems 24
High Dynamic Range Versatile Front-End for Vision
Systems 25
A High-Performance 2.4 GHz RF Front-End in a 90 nm
Process 26
Direct Modulation RF Transmitter and Super-
Heterodyne Low-IF Receiver Development Platform for
868 MHz and 915 MHz ISM Bands 27
Quasi-Harmonic Quadrature CMOS Relaxation
Oscillator 28
Silicon Resonators: Thermal Compensation and
Q Factor Optimization 29
icycam, a System-On Chip (SoC) for Vision
Applications 30
Programmable Multi-Processor Engine for Ultra-Low-
Power Single-Chip DVB Receiver 31
PHOTONICS 33
Miniaturized 360°-Camera Module for Collision
Avoidance 34
Optoelectronic Test Equipment for Image Sensors and
Systems Qualification 35
Highly Integrated Optical Linear Encoder 36
Compact Illumination Modules Based on High-Power
VCSEL Arrays 37
Generic Framework for Feature Extraction in Vision 38
Efficient Screening and Formulation Optimization for
Polymer LEDs 39
Polymer LEDs Patterned by Ink-Jet Printing 40
Optical Fill Factor Enhancement for Smart Pixels 41
MICRO AND NANOTECHNOLOGY 43
Dissolved Oxygen Sensor with Self-Cleaning and Self-
Calibration 44
Microfabricated Membranes for Cell Layer Culture and
Analysis 45
Metal Micro-Parts Fabrication 46
Scintillating Fiber Probes for Neurophysiology 47
Towards an Optical Switch with J-aggregates
Monolayers 48
Colour Filters Using Polystyrene Microspheres 49
Towards Plasmon Enhanced Detectors 50
Unique Marking for Traceability and Anti-Counterfeiting
Applications 51
Sol-Gel based Nanoporous Layers as New Sensing
Interfaces 52
High Aspect Ratio Nanopores in MEMS Compatible
Substrates 53
Nanoporous Membranes for Medical Diagnostics and
Drug Discovery 54
Stimuli-Responsive Surfaces and Smart Coatings 55
Parallel Nanoscale Dispensing of Liquids for Biological
Analysis 56
Electrospun Scaffolds for Tissue Engineering 57
Detection Methods for Nanotoxicology 58
Using Microtopography to Study Cell Elasticity 59
Composite Materials for Bone Implants 60
Simultaneous Detection of Four Antibiotic Families in
Milk for Customer Safety 61
Smart Wound Dressing with Integrated Biosensors 62
Biosensors for Drug Prevention 63
Food Safety with the Help of a Miniaturized Laboratory 64
Wearable Biosensors in Protective Clothing 65
3

NANOMEDICINE 67
Robust Label-Free Biosensor using BRIGHT
Technology 68
X-Ray Microscopy and Micrometer-Resolution
Computer Tomography 69
SYSTEMS ENGINEERING 71
Micro-Vibration Analysis Setup for MEMS and MOEMS
Characterization 72
Clinical Validation Results of the Long-Term Medical
Survey System 73
ActiSmile – A Portable Biofeedback Device on Physical
Activity 75
Prediction of Neurocardiovascular Events 76
Reaction Sphere for Attitude Control 77
Continuous Arterial Blood Pressure Monitoring: Can
the Cuff Be Got Rid of? 78
WISE – Wireless Solutions for the Aeronautics Industry 79
UWB Antenna with Improved Bandwidth and Spatial
Diversity using RF-MEMS Switches 80
FM-UWB – A Low Data Rate (LDR) UWB Approach
with Short Synchronization Time and Robustness to
Interference and Frequency-Selective Multipath 81
A Wireless Sensor Network for Fire and Flood
Detection at the Wild and-Urban Interface 82
Exploiting Directive Antennas for Wireless Sensor
Networks 83
A MAC Protocol for UWB-IR Wireless Sensor Networks 84
Optimum Operating Regimes for Wireless Sensor
Networks 85
Wireless Sensor Networks for Monitoring Cliffs in the
Alps 86
Control Electronics for Bio-Sensing Textiles to Support
Health Management 87
Wearable Systems to Protect Rescuers and
Firefighters during Operations 88
MEMS Based Miniature Catheter Probe for Ultrasound
Imaging 89
MICROROBOTICS 91
NanoHand – A System for Automated Nano-Handling –
An Integrated EU Project 92
Microfactory – A Flexible Assembly Platform 93
Isolation and Reversible Immobilization of Single Cells 94
Bonding of Glass or Silicon Chips with a Self-Sealing
Photostructurable Elastomer 95
Sensor and Connector Integration into Microfluidic
Systems using Biocompatible Tape Gaskets 96
Pressure Sensing Strip for Rapid Aerodynamic Testing 97
Pressure Sensing Strip – Packaging Aspects 98
4
Flip Chip Bonding on Polymers – Die Attach and Leak-
Tight Sealing 99
Optical / Fluidic Integration of Silicon-Based Hollow
Waveguides 100
Novel Injection-Free Method for Intraepidermal
Delivery of Large Molecular Weight Drugs 101
TIME AND FREQUENCY 103
PRN-cw Backscatter Lidar Prototype 104
Space Hydrogen Active Maser 105
COMLAB 107
Quality Control 108
ANNEXES 109
Publications 109
Proceedings 110
Conferences and Workshops 113
Competence Centre for Materials Science and
Technology (CCMX) and National Center of
Competence in Research (NCCR) Projects 121
Swiss Commission for Technology and Innovation
(CTI) 121
European Community Projects 122
European Space Agency (ESA), European Southern
Observatory (ESO) and Astrophysical Instrument
Projects 123
Industrial Property 124
Collaboration with Research Institutes and Universities 124
Teaching 126
Theses 129
Commissions and Committees 130
Prizes and Awards 132

PREFACE
Dear Reader,
In this report, CSEM presents the main results of its research
activities during the year 2007. Our research is aimed at
commercial innovation and is very much orientated towards
product applications. Using the know-how resulting from this
special research, we maintain and increase our technology
know-how, in order to create and develop our so-called
technology platforms.
We have defined seven priority domains for CSEM:
• Integrated Systems for Information Technology
• Photonics
• Micro- and Nanotechnology
• Nanomedicine
• Systems Engineering
• Micro robotics and Packaging
• Time and Frequency
It should be noted that the research activities, as described in
the following pages, are financed by federal (80%) and
cantonal funds (20%). We would like to thank all public
authorities, federal and cantonal, who made this report
possible!
We use our technology platforms for three main strategic
goals:
1. To guarantee the sustainability of our technology
competences and to be able to remain at the forefront
of micro- and nanotechnology and related system
engineering technology.
2. To make these competences available to our industrial
customers, thus bringing new technologies to new
markets.
3. To create start-ups in cases where new product ideas
are not taken up by industry in Switzerland.
As underlined above, CSEM research activities have mainly a
commercial goal. Our measure of success is therefore the
number of commercial applications and of patentable ideas.
We would like to thank all our partners (EPFL, IMT, ETHZ,
CEA / Léti-Liten, Fraunhofer Group Microelectronics VµE, and
many others). And, most of all, we would like to thank all who
have contributed to this report.
I hope you will like it!
Thomas Hinderling
CEO, CSEM
5

RESEARCH ACTIVITIES IN 2007
Alex Dommann
Today, industries are looking for complete solutions. In
particular, innovative products exhibit a technological
complexity, which can seldom be handled by a single
technology provider. One of CSEM strengths is to offer this
wide spectrum of technologies “under one roof”.
CSEM is proud to offer its industrial clients a rich portfolio of
technologies and a sound know-how of how to apply and
realize innovative products based on Micro and
Nanotechnologies. To maintain this portfolio in a healthy state
the Swiss Federal and Cantonal Governments provide the
necessary funding to run an applied research program. In the
frame of the applied research nine multidisciplinary integrated
projects (MIPs) built on several existing CSEM technologies
were launched. MIPs are planned on a tight time-schedule of
typically 2 years from the beginning to the realization of the
demonstrator. Based on the market-oriented research strategy
of CSEM ten MIPs were selected. A larger interdisciplinary
demonstrator project is Solar Island (see below) fully financed
externally but also dwelling on many different resources of
CSEM, including industrialization.
Further details on the nine MIP activities can also be found in
this Scientific and Technical Report.
ThruCOS – From Biosensor Chip to Robust Analytical
System
In order to accurately control a biomolecular reaction, it is
necessary to control the fluidic flow as well as the temperature
of the reaction. Therefore, the wavelength interrogated optical
sensing system (WIOS), previously developed at CSEM, has
been updated with a fluidic cartridge and a temperature
stabilized measurement chamber. In the future, this system
will be industrialized by the start-up company Dynetix.
Counterfeit – Machine Readable Covert Security Feature
By combining Micro and Nano technologies CSEM developed
a security system to directly mark products and verify their
authenticity. Due to forged products various industry sectors
experience huge damages accounting to several hundred
billion US Dollars a year. The development and
implementation of new security systems opens a huge market
to be exploited. In order to meet these requirements, CSEM
designed a new system showing two main characteristics:
• A random pattern which is difficult to be copied was
developed as a main security feature.
• In order to read those random patterns an instrument was
developed which is able to read those features only by
authorized persons.
MicroMec – Microtechnology for Silicon Compliant
Structures
The target of this project is the development of a
microfabricated silicon compliant structure for mechanical
applications and its understanding of the aging behaviour.
MEMS can be made highly reliable, but it must however be
noted that the failure modes of MEMS can be different from
those of solid-state electronics. Therefore testing techniques
are developed to accelerate MEMS-specific failures.
Monocrystalline material and, especially, silicon is
preferentially used due to its potential resistance against
aging.
ArrayFM – An Atomic Force Microscope Using
2-Dimensional Probe Arrays
In this multidisciplinary integrated project, an atomic force
microscope able to investigate large sample surfaces with
nanometric resolution was developed. Instead of a single
probe, this novel microscope uses a 2-dimensional array of
probes operating in parallel. Applications of this microscope
include the biology domain, quality control, as well as material
and surface characterization.
MicroStruc – Integrated Optical Polymer Platform,
Low Cost Assembly and Packaging
An integrated optics platform based on polymers as a low-cost
alternative to glass and semiconductor waveguides has been
developed from the design to the complete assembly and
packaging of the devices. Although silica-on-silicon PLCs are
well established they are still rather expensive as the
processing and packaging is costly. Therefore, polymer PLCs
potentially provide a promising alternative if low cost over the
whole manufacturing process can be obtained. First
demonstrators were already built.
Encoder – Nanometric Optical Absolute Position Encoder
An optical absolute position encoder principle is presented
which can combine many attractive features such as 24 bit
resolution per 100 mm, compact design, optic-less shadow
imaging, sampling rate exceeding 1 MHz and robustness. The
detectable displacement is several hundred times smaller than
the wavelength of the light and only 10 times larger than the
diameter of the silicon atom.
RISE – the Rich Sensing Concept
Within the RISE project a camera-based wireless sensor
network for people detection and tracking purposes has been
implemented. This sensor network, which is based on three
vision sensors and two 3D time-of-flight cameras, is an ideal
test-bed for long-term operational tests and the development
of advanced algorithms. Furthermore, the installation is well
suited for life demonstration purposes.
PackTime – Zero-Level Packaging of Silicon Time-base
The development of a thermally compensated silicon timebase
and the associated packaging to yield a miniature
vacuum-sealed cavity around the resonator requires
multidisciplinary competences in the fields of IC, MEMS
design/fabrication, packaging, finite element modeling and
metrology. This is the goal of the PackTime MIP.
7

TissueOptics – Portable SpO2 Monitor: A Fast Response
Approach, Tested in an Altitude Chamber
Altitude is hazardous for the human body, with the oxygen
delivery to the cells being jeopardized. The prototype of an
advanced oxygen saturation monitoring sensor, embedded in
a commercial earphone, was successfully tested in an altitude
chamber.
TUGON – Compact MEMS-based Spectrometers for Infra-
Red Spectroscopy
Deformable MEMS diffraction gratings have great promise as
tuning elements for external cavity lasers and for compact
spectrometers. The challenge is to make high efficiency
tunable MEMS gratings and incorporate them into practical
devices. CSEM successfully designed, fabricated and tested
MEMS gratings. Their spectral response was tested and the
potential to design ultra-compact spectrometers based around
this technology was shown.
Solar Islands – A Novel Approach to Cost Efficient Solar
Power Plants
Existing Solar Power Plants are too small, need complex
constructions and drive systems to follow the altitude of the
sun and have a limited use factor of the area. Therefore the
generated energy is too expensive. The target of the new
concept “Solar Islands” is to improve all these cost factors and
to end up with a cost per kWh which is competitive with the
energy costs of today. Furthermore the design as a floating
“island” allows not only the application on land, but also on
lakes, lagoons or on high sea. The vision is to build very large
islands, floating on the pacific, that could contribute 1/4th of
the estimated global energy demand in 2030.
In 2007 the CSEM filed 23 new patent applications, 34
invention reports were submitted for examination and
extension of 21 patents on prior patent applications in different
countries were filed in.
From the collaboration agreement between CEA / Léti and the
Fraunhofer Group Microelectronics (VµE) three working
groups emerged: the polymer platform, the joint design team
and the joint reliability team. It is also important to note the
creation of two new divisions at CSEM: Time and Frequency
in Neuchatel and Nanomedicine in Landquart.
8

ThruCOS – From Biosensor Chip to Robust Analytical System
G. Voirin, R. Ischer, E. Bernard, G. Suarez, J. Auerswald, L. Davoine, M. Wiki, S. Berchtold, N. Schmid
In order to accurately control a biomolecular reaction, it is necessary to control the fluidic flow and the temperature of the reaction. Therefore, the
wavelength interrogated optical sensing system (WIOS), previously developed at CSEM, has been updated with a fluidic cartridge and a
temperature stabilized measurement chamber. In the future, this system will be industrialized by the start-up company Dynetix.
In recent years, CSEM has developed a biosensor platform
based on glass chips. It is a general platform that has been
used to demonstrate the potential of the wavelength
interrogated optical sensing system (WIOS). However, this
platform must be adapted to fit new applications, for example,
an analytical laboratory system or a specific detection system
for antibiotics [1] . Therefore, a specific fluidic system which
allows several re-configurations has been developed. In
addition, a temperature controller has also been integrated
into the fluidic chip system to improve the reliability of the
measurements.
The glass chip consists of a glass substrate covered by a high
refractive index waveguide layer, and several grating regions
which form a matrix of sensing pads on the chip. Specific
recognition molecules can be attached to each grating pad as
a means of detecting different molecular targets. The specific
binding of molecules translates into a change of the refractive
index of the sensing layer. The refractive index is measured
by determining the resonance wavelength of the waveguide
grating pads using a wavelength tunable laser. To this end,
the laser wavelength is periodically swept while the coupled
light intensity is recorded. The laser illuminates eight grating
pads simultaneously which are independently analysed.
The designed fluidic cartridge is divided in two parts: the first
part is a support for the glass chip that defines the microfluidic
channels over each of the grating pads using a thickness
controlled double sided tape; the the second part defines the
fluidic channels for addressing each individual sensing pad.
Two different fluidic circuits have been designed for a
multipurpose laboratory analytical system. In one design, each
pad is addressed individually; there is one fluidic inlet and one
fluidic outlet per grating pad. In the other design, the grating
pads are serially addressed and the cartridge has only one
inlet and one outlet (Figure 1). The first design will be used for
the functionalization of the grating pads with different capture
molecules, while the second design will be used to test a fluid
sample for different target molecules in a single measurement.
IN
OUT
Cross section
4cm
Cartridge thinned down
ca. 0.5mm
for temperature stabilization
of flow-cell region
Size ca. 8mm x 14mm
Fluidic Gasket
- double side adhesive tape
- patterned by laser cutting
WIOS Chip
Figure 1: Schematic of one of the fluidic circuitries in the cartridge
Fluidic cartridges were fabricated using micromilling
technology in PMMA (Figure 2). Fabrication of the WIOS chips
with replication technologies in plastic substrates was also
performed; however, the performances are not yet sufficient
and the fabrication will be optimized.
For analytical applications in the laboratory, the temperature
of the biomolecular reaction must be controlled and
reproducible. In order to maintain a fixed temperature on the
chip and in the measurement fluid, the cartridge is enclosed in
a temperature stabilized measurement chamber. The
temperature of the chamber is then set using a Peltier element
controlled with a feedback-loop system.
Figure 2: View of the fluidic cartridge with one inlet and one outlet
The system depicted in Figure 3 was used successfully in a
set-up phase to implement the immunoassay protocol for
antibiotic detection on the WIOS instrument in the frame of the
CCMX project Lab-On-A-Chip [1] . The temperature control
system is able to stabilize the temperature to within 0.01°C in
the range of 15 to 40°C.
Figure 3: Temperature stabilization system including the cartridge
WIOS and supporting development have lead to the creation
of the start-up company Dynetix [2] , which will take over the
industrialization and the commercialization of the analytical
system for laboratory applications.
This work was funded by the OFFT, the cantons of Central
Switzerland, the Micro Center Central Switzerland (MCCS),
and European Projects FP6-NMP-STRP-032131 & NMP3-CT-
2007-026549. CSEM thanks them for their support.
[1] G. Voirin, et al., “Simultaneous Detection of Four Antibiotic
Families in Milk for Customer Safety”, in this report, page 61
[2] www.dynetix.ch
Inlet
Outlet
9

Counterfeit – Machine Readable Covert Security Feature
J. Pierer, U. Gubler, N. Blondiaux, R. Pugin, C. Keck, H. Walter
By combining Micro and Nano technologies CSEM has developed a security system to directly mark products and verify their authenticity.
Due to forged products various industry sectors experience
huge damages accounting to several hundred billion US
Dollars a year [1] . Consequently, extensive efforts are made to
increase protection of products at risk. The development and
implementation of new security systems opens a huge market
to be exploited.
However, to understand this market, one has to understand
the characteristics of security features. Most safety features
and safety equipment are safe only for a short period of time,
depending on how long it takes for forgers to counterfeit the
technique. Extending the secure period of a safety device is
therefore one of the most important requirements when
developing new security systems.
In order to meet these requirements, CSEM designed a new
system showing two main characteristics:
• A random pattern [2] which is difficult to be copied was
developed as a main security feature
• In order to read those random patterns an instrument was
developed which is able to read those features’, but is no
use to somebody who does not know what to look for.
By process control these patterns can be designed to meet
certain specifications with regard to the features of average
size and consequently average period. Their organization,
however, remains completely random.
The coherent light of a laser is used to illuminate the pattern.
The light is scattered on each element of the structure. Every
single element can then be seen as a new source of light.
Investigating the intensity of the scattered light at any point in
space will result in a value given by the superposition of the
light of all these sources. Depending on incidence angle,
structure period and wavelength of the light one gets a
particular intensity distribution. However, since the features
are randomly aligned the image shows a so called speckle
pattern (Figure 1).
Figure 1: Image of a speckle pattern on a paper target, left: small
spot illuminated, right: large spot illuminated
When illuminating a small spot of the security feature (about
30 µm) a well distinguishable speckle pattern becomes
visible. By enlarging this area up to a few millimetres, the
speckles are averaged and a smooth distribution is visible.
10
Analyzing characteristic parameters of the speckle pattern or
the smooth distribution identifies uniquely either a particular
security item (e.g. credit card) or the technology with which
the pattern was created. We have built a small electronic
prototype to demonstrate the feasibility and ruggedness of this
new technique.
A small laser diode with an integrated focusing lens was used
as source, a silicon photodiode array as detector to build the
prototype. All components, including a micro controller, were
assembled on a printed circuit board. The micro controller
compares the sample under investigation with an inbuilt
reference and communicates the result via a green/red LED to
the human observer. For obvious reasons credit cards were
chosen to demonstrate the new security feature. The credit
card is inserted into the device through a standard smartcard
holder. The cardholder holds the credit card in place with a
repeatable accuracy exceeding 40 µm, which is sufficient for
these purposes. As can be seen in Figure 2 the entire setup
fits into a small box leaving plenty of space.
Figure 2: Demonstrator
The results of this project have proven that the implementation
of these newly developed security features is possible with
very simple low cost components. CSEM security system is
difficult to counterfeit and is mass producible. The developed
authentication device is easy to use, compact and can be built
in into other devices, such as automatic teller machines.
CSEM new security features offer a promising way to prevent
counterfeiting for an extended period of time.
[1] G. W. Abbot, L. S. Sporn, Trademark Counterfeiting § 1.03[A]
[2] Patents pending

MicroMec – Microtechnology for Silicon Compliant Structures
C. Verjus, J.-M. Major, T. Overstolz, A. Hoogerwerf, A. Ibzazene, A. Neels, A. Schifferle, A. Dommann
The target of this project is the development of a microfabricated silicon compliant structure for mechanical applications and its understanding of the
aging behaviour.
MEMS can be made highly reliable, but it must however be
noted that the failure modes of MEMS can be different from
those of solid-state electronics. Therefore testing techniques
must be developed to accelerate MEMS-specific failures [1] .
Monocrystalline material and, especially, silicon is
preferentially used due to its potential resistance against
aging. However, quantified results of this fact are rarely
published. The reasons are manifold; however they are also
related to the surface roughness as well as to the defect
concentration of the etched surfaces due to the ion
bombardment [2] .
Deep reactive ion etching (DRIE) of silicon-on-insulator (SOI)
substrates allows the fabrication of structures with arbitrary
shapes (2D) that are vertically extruded by removing excess
silicon.
Test structures can be built from single crystalline silicon by
DRIE processes. Mechanical tests on these structures in
relation with simulations of stresses and the experimental
determination of the strain / stress behavior and defect
analysis by High Resolution Diffraction Methods (HRXRD)
give very important information about the device and its long
term stability. A silicon beam structure processed by DRIE
(Figure 1) has been studied. Simulations have been done
related to mechanical shifts applied to the entire silicon
structure which results in the generation of strain in the small
silicon beams having a thickness of 50 µm. In dependance of
the position of the beam in the structure, stresses ranging
from about 60 to 1100 MPA are calculated by simulations.
Figure 1: Silicon beam structure processed by DRIE
High resolution x-ray diffractometry (HRXRD) measures the
strain of a crystal. This is an accurate, non destructive method
applied in the field of MEMS to obtain quantified results on the
crystalline disorder.
CSEM therefore applies an X-ray rocking curve method, which
measures the strain of a crystal as well as the defect
concentrations.
Applying a mechanical force to a perfect silicon single crystal
results in a deformation which is directly related to a change of
the crystal strain profile. In addition, reciprocal space mapping
(RSM) visualizes the strain generation related to the bending
of the thin Silicon beam. The appearance of diffused
scattering in the RSM (Figure 2) is related to the beam
bending strain. Elastic deformation in the test structure was
observed.
Figure 2: Diffused scattering in the RSM of compliant structure
The study of mechanical tests combined with simulations and
related HRXRD measurements results in a better
understanding of the material properties. The generation of
defects in the material and their increase related to
mechanical stresses or other environemental influences is an
important issue as it is directly related to the device
performance and its long term stability.
[1] A. Dommann, G. Kotrotsios, A. Neels, MEMS Reliability and
Testing, MST News, (2007)
[2] E. Mazza and J. Dual, Mechanical behavior of a µm-sized single
crystal silicon structure with sharp notches. J. Mechanics and
Physics of Solids 47 (1999) 1795-1821
11

ArrayFM – An Atomic Force Microscope Using 2-Dimensional Probe Arrays
A. Meister, J. Polesel-Maris, S. Dasen, G. Gruener, M. Schnieper, T. Overstolz, A. Vuillemin, C. Gimkiewicz, R. Ischer, P. Vettiger,
H. Heinzelmann
In this multidisciplinary integrated project, an atomic force microscope able to investigate large sample surfaces with nanometric resolution was
developed. Instead of a single probe, this novel microscope uses a 2-dimensional array of probes operating in parallel. Applications of this
microscope include the biology domain, quality control, as well as material and surface characterization.
Since the emergence of the atomic force microscopy (AFM) in
the eighties, the topographic investigation of a sample surface
at a nanometric scale has become a standard technique. AFM
techniques can also be used to measure various kinds of local
interactions, such as magnetic, electrostatic, or binding forces,
electrical conductivity, or to determine mechanical properties
such as elasticity or friction. Standard AFMs use a single
probe, and, due to the scanning process, are rather slow in
terms of data acquisition. The aim of this project is to develop
an AFM functioning with a large probe-array instead of a
single probe, increasing thus the throughput of the instrument.
The realized instrument is shown in Figure 1. The
implementation of arrays instead of a single probe requires
new functionalities compared to a standard AFM instrument,
such as the parallel read-out of each probe, the spatial
alignment of the probe-array above the sample surface, and a
dedicated software to drive the instrument and for the user
interface. The correct positioning of the probe-array above the
surface is realized using a micropositioning stage with 6 axis
of freedom (Hexapod) with micrometric accuracy. The sample
is mounted on a piezoelectric nanopositioning stage, and is
scanned with a nanometric precision while the array probes
the sample surface.
Figure 1: Developed AFM instrument that is able to operate with an
array of probes in parallel
In contrast to standard AFMs, where the read-out of the
cantilever deflection is detected using a reflected laser beam,
in this instrument the parallel read-out of the cantilever-array
is based on optical interferometry using a Linnik
interferometer. The interferogram, which arises from the
combination of both reference and measuring optical beams,
is detected by a CMOS camera and analyzed by the software.
The characterization of the optical set-up showed an ability to
measure cantilever deflections as small as 1 nanometer.
The development and fabrication of the probe arrays made of
micro-cantilevers is another important issue. Such arrays are
12
not today commercially available, and have therefore also
been developed within this project. Since the cantilever
deflection detection is not integrated in the probe array, this
latter can be passive, and thus be produced in a cheap way.
Two different processes leading to two different and
complementary kinds of probes were developed. The first
process relies on a sol-gel replication of the probe arrays in a
polymeric structure, which are foreseen as disposable probe
arrays to be used for parallel force spectroscopy in biology.
The second process is based on micromachining of silicon
wafer, and enables the production of cantilever with sharp tips
dedicated to high resolution imaging. Examples of realized
probe arrays are shown in Figure 2.
Figure 2: Left: Optical micrograph of a probe array fabricated by solgel
replication process (scale bar: 500 µm). Right: Scanning electron
microscope micrograph of a silicon probe array fabricated by
micromachining.
The ability of this instrument to operate AFM cantilever arrays
opens new application domains, such as multi-parameter
surface investigation using a probe array with different
cantilever functionalities, parallel force spectroscopy with
improved statistics, or large scale topographic imaging. The
application field covers:
• Quality control: metrology, surface roughness, defect
analysis.
• Biological and medical applications: parallel cell
indentation (determination of the cell elasticity), parallel
force spectroscopy to measure cell-cell interaction or
antibody-antigen binding (to detect the presence of the
target molecule on the receptor molecule in affinity
assays).
• Large scale imaging: topographic characterization at a
nanometric range, large scale surface studies such as
friction or elasticity with picoNewton resolution.
The partial support of the Swiss Federal Office for Education
and Science (OFES) in the framework of the EC-funded
project NaPa (Contract no. NMP4-CT-2003-500120) is
gratefully acknowledged.

MicroStruc – Integrated Optical Polymer Platform, Low Cost Assembly and Packaging
A. Stump, P. Schüepp, T. Overstolz, C. Bosshard, U.Gubler
An integrated optics platform based on polymers as a low-cost alternative to glass and semiconductor waveguides has been developed from the
design to the complete assembly and packaging of the devices.
Planar lightwave circuits (PLCs) are replacing optical modules
with single elements assembled together more and more. The
integration of optical functionalities in a planar design with
batch processing can be seen analogous to the shift from
single electronic components to integrated microelectronics.
Unlike in microelectronics no standard material exists like
silicon. Although silica-on-silicon PLCs are well established
they are still rather expensive as the processing and
packaging is costly. Therefore, polymer PLCs potentially
provide a promising alternative if low cost over the whole
manufacturing process can be obtained.
The polymer PLC technology platform developed in the past
years at CSEM addresses these issues:
• The waveguide material can be produced inexpensively in
volumes.
• The structuring of the PLC is based on direct UVpatterning,
which saves cost compared to the traditional
dry-etch process (as e.g. silica-on silicon technology)
• The assembly is carried out passively in a pick-and-place
process without cost and work intensive active alignment
• The encapsulation of the assembly is done by a molding
process similar to the electronics and IC industry.
Figure 1: Sketch of encapsulation approach: the assembly is inserted
in the pre-form and filled with a sealant polymer. To reduce stress on
fibers boots are provided on both ends.
The encapsulation of PLC assemblies is an important part of
the process. Special preforms were designed and injection
molded. The trough is a LCP (liquid crystal polymer), which
acts as a barrier for gas or humidity to diffuse through the
package wall. The feedthroughs for the fibers are U-shaped
and the fiber boots molded from silicone fit exactly into these
U-holes. At the end of the boots a small hole allows threading
of the fibers (Figure 1). Due to this design the insertion of the
assembled PLC into the preform is straightforward. The boots
are put on the fibers and then pushed into the preform.
Figure 2: Sketch of the approach to package PLCs with electrodes.
As the PLC is wider than the carrier, the electrodes on the PLC are
still accessible.
In the case of thermo-optic devices the electrodes on the PLC
have to be contacted after the flip-chip step. In this approach
the PLC is designed wider than the carrier underneath so that
the electrodes are still accessible after the flip-chip step
(Figure 2). The overall process is simple and low cost. Before
molding the assembly into the package, electrical legs can be
connected to the PLC (Figure 3).
Figure 3: Model of a thermo-optic PLC with electronic contacts in the
encapsulated module built up as described above.
Although the main application area is the telecom market, a
low-cost integrated optics platform with an adequate
packaging technology is also interesting for other fields.
Various special applications in the area of sensing are
possible such as integrated spectrometers or interferometers,
hybrids with micro-fluidics in life sciences, or layouts for gas
sensing.
This work has been supported by the Micro Center Central
Switzerland MCCS.
13

Encoder – Nanometric Optical Absolute Position Encoder
P. Masa, E. Franzi, J. Pierer, P. Glocker, J.-M. Mayor, D. Fengels
An optical absolute position encoder principle is presented which can combine many attractive features such as 24 bit resolution per 100 mm,
compact design, optic-less shadow imaging, sampling rate exceeding 1MHz and robustness. The detectable displacement is several hundred times
smaller than the wavelength of the light and only 10 times larger than the diameter of the silicon atom.
Combining all the attractive features in a position encoder
such as high-resolution, absolute, compact, high-speed is a
real challenge today. Such an encoder clearly has a great
potential in various fields like robotics, automation, machine
tools, automotive, aerospace; just to mention a few.
An optical absolute position encoder technology developed at
CSEM has the potential to combine all these attractive
features. Nanometric resolution has been established using
ultra-compact USB camera, linear glass scale, LED
illumination, without the need for optics, as shown in Figure 1.
Note that the detectable displacement is several hundred
times smaller than the wavelength of the light and only
10 times larger than the diameter of the silicon atom. Highspeed
opto-ASIC implementation by CSEM proved that
sampling frequency of such an encoder may exceed 1MHz [1] .
Optic-less shadow-imaging permits compact design and major
cost reduction.
Figure 1: Shadow imaging experimental setup consisting of a
compact USB camera, transparent scale and LED illumination (LED
not shown here)
Coarse absolute position measurement is obtained by
decoding the subsection of the Manchester code (typically
8-16 bits), which is seen at a given position by the sensor.
Fine relative position measurement is attained by Fourier
analysis of the regular grating at the fundamental frequency.
Robustness, precision and very high resolution is guaranteed
by heavily oversampling the pattern (typically 8-16 pixels per
pattern period) and relying on the phase information which is
distributed in the entire image among hundreds or thousands
of pixels. The fine measurement principle is shown in
Figure 3. One possible interpretation of the method is that
each pixel represents one point in the “cloud of
measurements” and the center of gravity gives the final result.
The combination of the coarse and the fine measurements
yields very high-resolution absolute position, typically 24 bits
for a Ø 32 mm rotary or 100 mm linear encoder. The
maximum attainable resolution scales linearly with the
diameter of the rotary or with the length of the linear encoder.
14
A flexible, customizable experimental/demonstrator platform is
under development, which is based on the icycam chip [2] . The
image captured by a 320 x 240 high dynamic range pixel array
is processed in real-time on the same chip by the 32-bit icyflex
processor. Prototyping of rotary, linear and even 2D position
encoders can be supported by this platform. One of CSEM
goals is to demonstrate the potential in robotics, to combine
the technologies of the absolute encoder and the PreciAmp
servo-drive to build the CSEM next generation direct-drive
MicroDelta robot.
Figure 2: Image of a double-track linear scale consisting of a 12 bit
Manchester code and 100 µm regular grating. Image obtained by
ultra-compact USB camera and shadow imaging.
Figure 3: Robust, high-precision position measurement principle
[1] A. Mortara, et al., “An Opto-Electronic, 18-bit/revolution Absolute
Angle and Torque Sensor, ISSCC 2000 Digest
[2] C. Arm, et al., “icycam, a System-On Chip (SOC) for Vision
Applications”, in this report, page 30

RISE – The Rich Sensing Concept
A. Hutter, D. Beyeler, A. Brenzikofer, E. Grenet, F. Rampogna, L. von Allmen, C. Urban, P. Nussbaum
Within the RISE project a camera-based wireless sensor network for people detection and tracking purposes has been implemented. This sensor
network, which is based on three vision sensors and two 3D time-of-flight cameras, is an ideal test-bed for long-term operational tests and the
development of advanced algorithms. Furthermore, the installation is well suited for life demonstration purposes.
The multi-disciplinary project RISE targets the elaboration of a
heterogeneous sensor network for the purpose of people
detection and tracking within home and building areas. As a
result of the first project phase, which ended in 2007, a
demonstrator has been implemented in the CSEM entrance
hall. The demonstrator is based on two different camera
types: low power vision sensors [1] and 3D time-of-flight
cameras [2] . Vision sensors exploit the contrast information of
the observed scene and are distinguished by their huge
dynamic range of 100 dB as well as the low power
consumption of 80 mW. 3D time-of-flight cameras, on the
other hand, provide a three-dimensional representation of the
observed scene. Within the RISE project the vision sensors
are used to detect and track persons and objects whereas the
3D time-of-flight cameras are utilized in order to provide
additional height information of the detected objects. Further
essential components of the system are the wireless
communication link together with the data fusion entity. In this
article the basic concept together with the implemented interworking
of the cameras and the wireless system is described.
The data fusion algorithm and the related issues are subject to
a separate article [3] .
The demonstration test-bed covers an area of approximately
150 m 2 . The vision sensors operate with a 2.6 mm fish-eye
objective, which in turn provides a relatively large field of
vision, e.g. the area that is observed by one particular camera.
As such, the vision sensors have overlapping fields of vision
and cover the entire entrance area ranging from the entrance
over the two entrance side areas to the reception desk. The
field of vision of the 3D time-of-flight cameras, which require
active illumination, is limited to an area with a diameter of
approximately 2 meters. One 3D camera is positioned close to
the entrance whereas the second 3D camera is located right
in front of the reception desk. The network coordinator, which
acts as wireless data concentrator, is located in a closed box
with wooden shielding right under the central monitor in the
reception hall. An illustration of the disposition of the different
vision sensors and the 3D cameras is presented in Figure 1.
Figure 1: Disposition of the vision sensors and 3D cameras in the
CSEM entrance hall
A new sensor platform that is capable of hosting both, the
vision sensor as well as the 3D camera, and that provides the
required processing and communication resources has been
designed. The sensor platform includes a Blackfin 533 digital
signal processor running at 500 MHz, 2 MB Flash and 32 MB
SDRAM memory, an Ethernet connection for test and
debugging purposes and a hardware socket that connects
different wireless modules. For the purpose of the RISE
project the use of the 2.4 GHz ZorgWave module [4] was
selected, since the communication characteristics of the
module together with the associated protocol stack respond
ideally to the throughput and delay requirements of the
system.
The communication concept foresees that each sensor node
communicates the position data of each detected object
together with a time stamp and some additional object
information – in total around 100 Bytes – to the network
coordinator. Transmission at regular intervals (about every
100 ms) is mandatory in order to guarantee tracking
consistency. In addition to this regular traffic, specific data
requests (as for instance the transmission of the currently
observed image) should be possible. This results in a required
data rate of approximately 8 kbps for the regular traffic of each
sensor node plus some additional bandwidth for the irregular
data request traffic. In order to comply with these
requirements the IEEE standard 802.15.4 (which is identical to
the basic protocol layers of the ZigBee system) was selected.
The network operates in beacon-enabled mode with a beacon
interval of 123 ms and the guaranteed time slot (GTS) option
of the standard is used to transmit the regular traffic of up to
seven sensor nodes. The GTS option allows contention-free
channel access meaning that data packets are transmitted
with guaranteed throughput and delay. It should be noted that
the GTS feature, which is not a mandatory option in the
standard, was implemented in the CSEM K15 stack. The GTS
portion requires approximately 44% of the available
transmission time between network beacons so that
approximately 67 ms remain available to accommodate
irregular data requests. This corresponds to a sustainable
data rate of approximately 15 kbps in situations with multiple
simultaneous data requests.
The RISE project demonstrator is fully operational and can be
visited at CSEM upon request.
[1] S. Gyger, et al., “Low-power Vision Sensors”, CSEM Scientific
and Technical Report 2004, page 17
[2] T. Oggier, et al., “Miniaturized 3D time-of-flight Camera with USB
Interface”, CSEM Scientific and Technical Report 2002, page 37
[3] E. Franzi, et al., “Data Fusion for Wireless Distributed Tracking
Systems”, in this report, page 24
[4] CSEM Wireless Sensor Networks, www.csem.ch/wsn
15

PackTime – Zero-Level Packaging of Silicon Time-base
D. Ruffieux, J. Baborowski, M. Fretz, S. Grossmann, C. Henzelin, I. Kjelberg, T.C. Le, J.-M. Mayor, A. Pezous, A.-C. Pliska,
A. Schifferle, G. Spinola Durante, Y. Welte
The development of a thermally compensated silicon time-base and the associated packaging to yield a miniature vacuum-sealed cavity around the
resonator requires multidisciplinary competences in the fields of IC, MEMS design/fabrication, packaging, finite element modeling and metrology.
The low power frequency and timing market relies almost
exclusively on quartz resonators to derive precise and low
aging references thanks to the availability of crystal cuts with
null first order temperature coefficient on frequency (TCF).
Silicon on the other hand appears quite attractive from a
miniaturization perspective but suffers from a severe
drawback with a TCF close to -30 ppm/°C whatever the
crystal orientation. Consequently, electronic compensation
that can possibly be combined with structural
compensation [1, 2] appears as one of the most promising
workarounds to reach performances similar or better than that
of AT-cut quartz crystal achieving null first and second TCF.
The development of such a high performance, miniature and
low power real time silicon clock (RTC) together with the
associated packaging technology entails multidisciplinary
competences in IC and MEMS design/fabrication, packaging,
FEM and metrology. The activities ongoing in each of these
fields are described in the following sections after an overview
of the system is presented. Figure 1 shows a cross-section of
the envisioned miniature whole silicon time-base that consists
of a rear side packaged silicon resonator integrated on a SOI
substrate that is assembled and interconnected by a flip-chip
and reflow process to an IC capping die generating the
thermally compensated clock. The reflow process is
performed under vacuum and should ensure hermeticity of the
cavity that is formed around the resonator to take advantage
of the high quality factor of the latter and minimize any aging
of the time-base.
Figure 1: Cross-section of the miniature zero-level packaged silicon
timebase with a vacuum-sealed cavity around the resonator
A FEM CAD model of the complete resonator including its
package has been developed to help determine the sensitive
parameters that affect the resonator frequency during and
following the assembly process and could then be responsible
for excessive aging. Thermo-mechanical simulations are also
very valuable to predict the performance of the compensated
time base that relies on a good matching of the resonator and
sensor temperature and that may be affected during thermal
transients. The lack of availability of precise data for the
stiffness of the materials involved in the fabrication of the
resonators and their temperature dependency has motivated
the development of an optical metrology bank [3] and dedicated
test structures that should help future resonator design and
allow more precise FEM analysis once measurement and
extraction is completed.
16
The resonator exploits a high-Q in-plane, longitudinal,
extensional mode and is formed of a T-shaped silicon beam,
typically 1000 x 250 µm 2 , anchored at its base end, with an
inertial mass at each extremity. Figure 2 shows some
extensional resonators after processing. The driving voltage is
applied on the piezoelectric layer only in the central part of the
beam. The resonators are built from a (100) oriented Silicon
on Insulator (SOI) substrate. Structure of the resonator
consists mainly of single crystal silicon that is oxidized on both
sides, and that is topped by AlN and its electrodes.
Polycrystalline piezoelectric (002) AlN films are deposited by
magnetron sputtering on Pt (111) electrode. A metal ring is
patterned around the resonators for subsequent assembly
with the capping wafer.
Figure 2: Microphotograph of fabricated resonators
Si resonators in extensional mode, oriented along with
a thickness of 105 microns, and activated by 2 micrometers of
AlN, exhibit a Q factor under vacuum of 140000 and k 2 eff
around 0.05%. Q factor at atmospheric pressure is up to
20000, and increases linearly when the pressure decreases.
In order to obtain the maximum Q factor the pressure must be
below 0.1 mbar. The measured impedance in air and under
vacuum is plotted in Figure 3. The resonance frequency of
these resonators is close to 960 kHz, the motional resistance
is in the range of 200 Ohm and the linear TCF is -28 ppm/°C.
Figure 3: Impedance plot of high Q resonator in air and vacuum

In order to optimize the performances of the resonator and
guarantee long-term frequency stability, one needs to perform
hermetic packaging under reduced pressure. The rear side of
the resonators is closed hermetically by low temperature
fusion bonding (with Si wafer) or by anodic bonding (with
Pyrex). Both methods require an extremely smooth surface of
the wafer.
The resonator chips are then vacuum encapsulated using
silicon caps (ultimately working ICs) and AuSn (80% wt Au)
soldering technology. Metallic alloy materials provide both
low-permeability sealing characteristics as well as electrical
conduction for the resonator driving interconnects. The AuSn
electroplating process was carried out at the Fraunhofer
Institute for Reliability and Microintegration (IZM FhG).
Vacuum sealing of the resonator chips is done through a twostep
process:
• Tacking of the sealing cap on the resonator chip at a
temperature below the AuSn melting point using flip-chip
• Reflow under vacuum in a dedicated oven
The tacking methodology proved to be successful. Taguchi
runs using thermo-compression parameters (temperature,
force, dwelling time) as variable experimental factors were
carried out.
Reflow process development, where resulting vacuum level is
monitored through Q factor measurements, is on-going.
A differential oscillator structure has been chosen to minimize
the circuit power dissipation despite the large shunt
capacitance of the resonator (~10 pF). A programmable
fractional divider is used to generate a thermally compensated
32768 Hz clock from the 960 kHz oscillator signal that drifts by
-28 ppm/°C. The output of a high resolution temperature
sensor integrated on the same die is used by a sequencer to
implement an open-loop compensation algorithm that requires
initial calibration of the resonator absolute frequency and
thermal drift. The state machine has been implemented on an
external FPGA to yield greater flexibility. Communication with
the IC to read the thermal sensor indication and update the
fractional divider ratio is ensured via a serial bus interface.
Figure 4 shows a photograph of a miniature packaged
resonator that has been glued above the IC mounted over a
printed circuit board. The close vicinity of the resonator and
the thermal sensor located within the IC minimize any thermal
gradient that would affect the compensation accuracy.
Extensive testing of the IC with the miniature packaged
resonators will be initiated once satisfactory vacuum levels are
reached within the micro-cavity to assess the performance of
the thermo-compensated time-base.
Figure 4: Photograph showing a chip on board assembly of a
miniature time-base
[1] J. Baborowski, et al., “Piezoelectrically Activated Silicon
Resonators”, IEEE Frequency Control Symposium, 1210-1213
(June 2007)
[2] B. Kim, et al., “Si-SiO2 Composite MEMS Resonators in CMOS
Compatible Wafer-Scale Thin-Film Encapsulation”, IEEE
Frequency Control Symposium, 1214-1219 (June 2007)
[3] J.M. Mayor, et al., “Micro-Vibration Analysis Setup for MEMS
and MOEMS Characterization”, in this report, page 72
17

TissueOptics – Portable SpO2 Monitor: a Fast Response Approach Tested in an Altitude
Chamber
C. Verjus, V. Neuman, J. Solà I Caros, O. Grossenbacher, S. Dasen, O. Chételat
Altitude is hazardous for the human body, with the oxygen delivery to the cells being jeopardized. The prototype of an advanced oxygen saturation
monitoring sensor, embedded in a commercial earphone, has been successfully tested in an altitude chamber.
Oxygen is vital to maintain the basic metabolism of cells in the
human body: in the absence of oxygen for a prolonged
amount of time, cells would die. In critical situations like
aviation, severe hypoxia periods reduce oxygen delivery,
leading subjects to unconsciousness and compromising the
security of the crew. Thus, continuous monitoring of oxygen
delivery to cells is a relevant indicator of the health of a
person.
For healthy people under normal oxygen delivery situations,
about 98% of haemoglobin (Hb) in the blood combines with
oxygen to form oxy-haemoglobin (HbO2). The so-called
arterial oxygen saturation (SaO2) is calculated as the ratio of
HbO2 to total haemoglobin (Hb + HbO2). When this saturation
parameter is assessed by means of optical non-invasive
techniques it is commonly known as SpO2.
Pulse oximetry is a widespread, non-invasive method used in
clinical environments to determine arterial oxygen saturation.
Two light beams of different wavelengths are injected into the
skin surface and transmitted or backscattered parts of them
are retrieved. The technique is then based on the photoplethysmographic
effect (measurement of a change of volume
by optical means) and on the local characteristics of the
absorption curves of hemoglobin and oxy-hemoglobin at two
different wavelengths.
SpO2 sensor products are available today, but they are
incompatible with comfortable and non-obtrusive long-term
monitoring. CSEM has launched a strategic activity to develop
oximeter probes for different body positions (finger ring, ear
cartilage, sternum, etc.).
Figure 1: Comparison between the blood oxygen saturation given by
the reference sensor from Biopac and calculated by the CSEM
sensor during the whole test.
TissueOptics is a CSEM Multidisciplinary Integrated Project
aiming at improving its expertise of non-invasive optical
measurements in human tissue. One of the innovations
already developed in this project is a dedicated electronic
18
including a servo-controlled loop and an offset correction to
improve the dynamic range of pulse oximetry sensors.
Figure 2: Test subject in the cockpit mock-up and computer logging
of the reference blood oxygen saturation value from the Biopac and
the value measured with the CSEM sensor.
The measurements were conducted during the cockpit
ventilation assessment tests of SolarImpulse [1] in the altitude
chamber of the Fliegerärztliches Institut der Luftwaffe
FAI/AMC Schweiz in Dübendorf. Two tests were performed on
this occasion with two different test subjects. The tests aimed
at obtaining in the shortest time possible the cockpit air
composition for oxygen and carbon dioxide, as it will change
at high altitude. Each test lasted about 4 hours. The time for a
climb to 3000 m was around 20-30 minutes. The altitude
chamber is internally ventilated, in order to provide normal
atmosphere conditions in the environment of the cockpit mock
up.
A Biopac Sensor, using a fingertip probe, connected to a
laptop computer logging the measured values acts as a
reference for the CSEM SpO2 sensor. The CSEM SpO2
sensor uses an earlobe probe integrated into an earphone.
The results calculated in real time by the CSEM sensor are
fully in agreement with the reference values from the Biopac.
[1] www.solarimpulse.com

TUGON – Compact MEMS-based Spectrometers for Infra-Red Spectroscopy
M. Tormen, R. Lockhart, J-M, Mayor, R. P. Stanley
Deformable MEMS diffraction gratings have great promise as tuning elements for external cavity lasers and for compact spectrometers. The
challenge is to make high efficiency tunable MEMS gratings and incorporate them into practical devices. CSEM has successfully designed,
fabricated and tested MEMS gratings. Their spectral response has been tested and the potential to design ultra-compact spectrometers based
around this technology has been shown.
In Optical MEMS, the family of diffractive MEMS is interesting
for a wide range of applications because they can be
compact, fast and their narrow spectra response can be used
in spectrometers and for tunable lasers [1] . Commercially
available diffractive MEMS are used in displays, in
spectroscopy and optical telecommunications [2, 3] .
Optical grating
Comb drives
Figure 1: Overview of a tunable MEMS grating. The white dotted
region denotes the optical grating which is actuated by four sets of
electrostatic comb drives.
CSEM has been developing a tunable MEMS grating
technology, and this report demonstrates how it could be
incorporated into a compact spectrometer. In the
spectrometer, the MEMS grating is stretched like an
accordion. The change in the size of the grating changes
directly the period of the grating and hence the wavelength
tuning of the grating. This method of tuning is completely
different from normal spectrometers where the grating is
rotated. The advantage of MEMS grating is that the complex
mechanics for controlling the rotation of the grating in the
standard configuration is replaced by simple electrostatic
comb drives which stretch the MEMS grating.
Figure 1 shows a processed MEMS device [4] which comprises
the tunable optical grating and the electrostatic comb drives
which stretch the grating. The device has been fabricated
using standard MEMS manufacturing techniques. The
complete die measures 6 x 3 mm, with a 1 mm x 1 mm
grating. The grating itself is formed from free-standing beams
with a 12 µm period and a 50% duty-cycle. The beams are
attached to each other using leaf springs. So that it can be
stretched in its plane, the grating is free standing.
One of the challenges is to make a MEMS grating that has a
high diffraction efficiency. A grating with a square profile is the
easiest structure to manufacture but has only about 40%
diffraction efficiency in the first order. In contrast, blazed
gratings can have efficiencies close to unity. In order to
achieve this, the gratings have been blazed using anisotropic
KOH etching. This technique is widely used to make
V-grooves. It yields smooth angled surfaces while maintaining
the mechanical properties of the grating beams. Extending
this technology to a MEMS device has been a challenge. The
MEMS grating shown in Figure 1 is actually a blazed grating.
Figure 2 : A minature monochromator in the lab. The light is coupled
into and out of the grating (bottom centre) using a pair of fibres and
collimating lenses. For scale the MEMS chip is 12 x 6 mm.
The spectral response of the MEMS grating was measured
using an optical spectrum analyser and a collimated white
light source in a configuration shown in Figure 2. The optical
system is extremely compact. The resulting spectra are shown
for different drive voltages in Figure 3.
A tuning range of 3% and subnanometer linewidths have been
achieved. Potentially 10% is achievable with the improved
mechanical design. The spectral response can be better
appreciated in Figure 4 taken for a 1.5 mm long fixed grating
made with the same MEMS process technology. A 25 db
rejection has been achieved experimentally.
Efficiency (Normalized)
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
5 mm
1505 1510 1515 1520
Wavelength (nm)
1525 1530 1535
Figure 3: The spectral response of the MEMS grating shown in
Figure 1 for several different drive voltages ranging from 0 to
55 volts.
A unique property of these MEMS gratings is that the
efficiency of the gratings is high at all wavelengths. Although,
the efficiency is strongly angular dependence, as the angle is
never varied, in contrast to standard scanning
monochromator, it remains constant. This means that the
same device can be used for a wide range of spectral regions
from the UV to the mid-IR. This versatility is very promising for
0V
5V
10V
15V
20V
25V
30V
35V
40V
45V
50V
55V
19

spectrometer applications so CSEM has targeted to miniature
monochromators as a demonstrator of this technology.
The next stage of this work will be to move towards a fully
packaged compact spectrometer. The near-IR has been
chosen to demonstrate the technology, although main
potential applications are excepted to be in the mid IR.
Several challenges remain, such as increasing the tuning
range, control of stray light, etc. In addition all the system
related issues such as drive electronics and the mechanical
housing need to be finalized.
20
1.0
0.8
0.6
0.4
0.2
0.0
Measured (Normalized)
Theory ‐ NA = 0.0011
810 812 814 816 818 820 822 824
Wavelength (nm)
Figure 4: Optical characterization and simulation. Optical
characterization has proven the expected high optical performance: a
linewidth of 0.4 nm at 800 nm has been demonstrated for a 1.5 mm
long blazed grating.
The MEMS gratings can also be used as the tuning element
for external cavity lasers. They have many advantages over
standard gratings because the mechanics to tune the grating
is built-in so the total module can be compact, rapid and
eventually low cost. The gratings are currently being tested
with external cavity tunable Quantum Cascade Lasers [5] . A
success here will lead to the very compact tunable Mid-IR
source.
CSEM thanks NCCR Quantum Photonics that partly funded
this work.
[1] H. Schenk, et al., “Photonic microsystems: an enabling
technology for light deflection and modulation”, SPIE, vol.5348,
Nr 1, (2004), 7-21
[2] www.siliconlight.com
[3] www.polychromix.com/html/products.htm
[4] M. Tormen, et al., “Deformable MEMS grating for wide tunability
and high operating speed”, SPIE, vol. 6114, (2006), 61140C
[5] C. Sirtori, J. Faist, F. Capasso, “The quantum cascade laser. A
device based on two-dimensional electronic subbands”, Pure
and Applied Optics, vol. 7, Nr. 2, (March 1998), 373-81

Solar Islands – A Novel Approach to Cost Efficient Solar Power Plants
T. Hinderling, Y. Allani • , M. Wannemacher, U. Elsasser ••
Existing Solar Power Plants are too small, need complex constructions and drive systems to follow the sun’s altitude and have a limited use factor
of the area. Therefore the generated energy is too expensive. The target of the new concept “Solar Islands” is to improve all these cost factors and
to end up with a cost per kWh which is competitive with today’s energy costs. Furthermore the design as a floating “island” allows not only the
application on land, but also on lakes, lagoons or on high seas. The vision is to build very large islands, floating on the pacific, that could contribute
1/4 th of the estimated global energy demand in 2030.
The generation of sustainable energy will become one of the
main challenges of our civilization for the coming decades.
Worldwide energy demand is expected to grow from about
10 GTep (Giga Ton Equivalent Petrol) in the beginning of the
century to 15-20 GTep by 2050.
Among the many renewable energy sources, the potential of
solar energy is at least one hundred times larger than any
other renewable energy source. Today, there are four main
classes of solar energy systems in operation or in
development:
• Photovoltaic panels (PV)
• Low temperature solar panels (collectors)
• Thermo-solar high temperature panels and systems
(100-350°C) also known as “Concentrated Solar Power”
(CSP) and higher temperature (800-1000°C), e.g. solar
tower
As costs for PV panels are still quite high, efficiency of the
energy conversion is quite low, and storage of produced
energy has not been solved, this technology is not appropriate
for bulk energy supply. Low temperature panels are only
useful for warm water supply for domestic and industrial use.
Therefore only CSP is a promising candidate for large scale
application.
Figure 1: Extra-Flat Concentrator (EFC)
Most of the currently build and planned CSP power plants [1]
make use of parabolic trough-shaped mirror reflectors, that
concentrate sunlight to receiver tubes placed in the trough’s
focal line. The tube contains a heat exchange fluid or direct
steam generation (DSG) is used. The steam is converted to
electrical energy in a conventional steam turbine generator.
The heat can be stored by using latent storage materials like
liquid salt in order to extend delivery of electric energy in the
evening hours.
As a lower cost alternative, Solar Islands will use extra flat
concentrators, built out of flat mirror glass blades which form a
Fresnel reflector, see Figure 1. The concentrators will not
follow the elevation of the sun, but its azimuth. To this end, the
concentrators are mounted flat on the platform. Thus all
elements of the platform will be passive, only the platform
itself will rotate in order to follow the azimuth.
Figure 2: Floating Platform
The platform will consist of an outer torus (e.g. steel ring). The
inner part is covered with a low-cost surface sheet (e.g. plastic
foil). An overpressure is applied below this membrane, thus
exerting a vertical force equal to the weight of the solar
thermal modules placed on the membrane, as depicted in
Figure 2. Only about 5 mbar overpressure is needed to carry a
load of 50 kg/m 2 . This novel design enables a simple turning
of the platform by using electric hydrodynamic motors.
Figure 3: Large Islands on open sea (computer graphic)
The same principle can be applied for land based platforms,
where the outer ring is simply swimming in a circular water
trench. In that case, drive wheels will be used for the island’s
propulsion.
Figure 4: Cross-section of land based Solar Island (computer
graphic)
21

As a first step, CSEM is building such a land based prototype
in the emirate Ras Al-Khaimah (RAK) with a diameter of 86 m,
see Figure 5. This island will be equipped with 68 solar
thermal modules, each of size 8 m x 8 m. The modules and
the entire thermal loop is designed and manufactured by the
CSEM startup Nolaris.
Figure 5: Prototype of diameter 86m (CAD Model)
The outer ring is designed as a torus of 2 m height, made out
of 6 mm thick steel. Figure 6 shows the first produced
segments.
Figure 6: Steel torus elements
A simple polyolefin foil of 2 mm thickness, enforced with some
polyester fibers, will be clamped to the torus and span the
entire inner part of the island. Spacing elements will be
arranged in linear rows in order to distribute the load of the
modules to the foils. Additionally, steel cables will be spanned
over the island in a 4 m x 4 m grid to stabilize the modules
and transmit horizontal wind forces to the torus. Intensive
FEM and wind simulations have been made to assure the
utmost stable orientation of the modules, see Figure 7.
Figure 7: Part of the CAD model (absorber tubes not shown)
22
At the centre of the island the feeding water will be supplied
by a pivotable joint. From there, the water will be distributed to
the modules. All modules of a row form one branch of this
network. The branches are in fact the absorber tubes, which
are mounted 4 m above the mirror blades. In a coaxial
manner, the feeding water floats through an inner pipe to the
end of the branch. Figure 8 shows the basic principles of the
absorber tube.
Figure 8: Design of absorber tube
The water will arrive preheated at the end of the branch and
will flow at this point to the outer pipe (Figure 9). On its way
back to the central tube, the water will heat up further and will
be transformed into steam. The steam will leave the island
through a pivotable joint and will drive a steam turbine which
is placed next to the island.
Figure 9: Water and steam network
The generated peak power of the prototype will amount to
approx. 1 MW, with an average power of 250 kW. The annual
energy production is expected to reach 2.2 GWh.
•
Nolaris SA, a CSEM Start-up
••
Independent mechanical designer, consultant to CSEM
[1] F. Trieb, H. Müller-Steinhagen, “Sustainable Electricity and
Water for Europe, Middle East and North Africa”, DESERTEC,
Whitebook of TREC and Club of Rome (2007).

MICROELECTRONICS
Christian Enz
The research activities conducted in the field of Integrated
Systems for Information Technology (ISIT) are focused on the
design of highly integrated systems targeting low-power and
low-voltage applications. The latter systems typically include
complex microelectronics Systems-on-Chip (SoCs),
embedding many functionalities on a single chip, together with
other heterogeneous devices such as RF passives,
resonators and filters, silicon time basis and sensors into
advanced Systems-in-Package (SiPs). The research is
organized around four different generic technology platforms:
• Digital SoC platform
• Sensory Information Processing platform
• Integrated RF Circuits and Systems platform
• RF and Piezoelectric Components platform.
The achievements made during 2007 in these different
platforms are discussed in more detail below.
The Digital SoC platform aims at developing all the key digital
components required in a SoC, including low-leakage
memories and highly energy-efficient processors. The latter
include the Macgic, a 4 MAC digital signal processor (DSP)
developed for intensive digital signal processing and the
icyflex, a 32-bit microcontroller core with additional DSP
capabilities, for simple signal processing. These processors
have now reached a certain degree of maturity and have
started to be integrated in several industrial SoCs. As an
example, four Macgic DSPs have successfully been used in a
programmable multi-processor engine for an ultra low-power
mobile digital TV. The icyflex has now become the heart of all
CSEM SoCs replacing the long-time used 8-bits CoolRISC
microcontroller. It is also used in the new generation of digital
vision sensors SoC called icycam.
The Sensory Information Processing platform implements
powerful vision systems that are able to extract essential
image features in real-time and at low-power. These features
include the three most important information categories that
are used by the basic operation of the human vision, namely,
the contrast (intensity variation), the direction of contrast
(feature orientation) and the motion (spatio-temporal contrast
variation). The new vision sensor platform has been migrated
from the former 0.5 µm CMOS process towards a 0.18 µm
process. In the former version, the contrast extraction and
calculation was fully done in the analog domain, making it
difficult to migrate. In order to take full advantage of
technology scaling, the core of the vision sensor architecture
has been profoundly modified and is now essentially digital.
This also allows taking advantage of the icyflex processor in
the newly designed icycam vision sensor SoC. The ability of
vision sensors to process the image feature locally enables it
to be used together with other vision sensors connected
together with a rather low data rate wireless channel. Such a
network allows performing data fusion of signals provided by
several vision sensors and 3D cameras in order to track
persons in buildings. Another SoC including the icyflex is used
for nanometric absolute position encoding. Such miniaturized
optical encoders have a great potential for applications in
robotics, automation and machine tools.
The Integrated RF Circuits and Systems platform mainly
targets ultra low-power short-range and low data rate
applications. A new development platform has been
engineered for the design of narrow-band RF transceivers
operating in the 868 MHz and 915 MHz ISM bands. It includes
an integrated front-end IC with a low-IF super-heterodyne
receiver architecture and a newly designed direct modulation
RF transmitter. The on-chip analog baseband uses a phaseto-digital
converter and is followed by a digital baseband
implemented in a FPGA in order to keep a maximum of
flexibility. This platform allows experimenting on different
modulation schemes. The efficient combination of MEMS such
as BAW resonators and ICs has always been a strong
research topic in the field of ultra low-power radio design.
After having realized a BAW RF front-end, the BAW is also
used in the frequency synthesizer. A new architecture is
proposed to take advantage of the low-phase noise but
circumvent the limited frequency tuning range of the BAW
VCO. It uses a quasi-harmonic relaxation oscillator featuring a
large tuning range compensating the limited one of the RF
VCO. This architecture is similar to the one used in the radio
that will be used within the PackTime MIP.
The new radio and synthesizer architectures mentioned above
rely heavily on the BAW and silicon resonators developed in
the RF and Piezoelectric Components platform. These
devices take advantage of the AℓN thin film piezo-electric
technology available at CSEM. Silicon MEMS resonators can
potentially achieve similar performance to crystal quartz with a
smaller size. However, they suffer from the high temperature
coefficient of silicon and imperatively have to be compensated
in temperature. This can be done electronically by using an
on-chip temperature sensor or by depositing an additional
layer of proper thickness made of SiO2 having a positive
temperature coefficient. Two families of Si-resonators have
been developed: temperature compensated 20 to 140 KHz
flexural resonators and high-Q 1 MHz extensional resonators.
These MEMS are activated thanks to an AℓN piezoelectric
layer, making them compatible with the voltages used in
SoCs.
The four technology platforms are evolving towards ever more
complex systems combining the different technologies. In this
sense there is clearly a convergence of the overall research
activity in this field. This concentration should help to solve the
important challenges that lie ahead. Among those we can
mention the migration towards ultra deep sub-micron CMOS
process, with its inherent leakage and parameter variability
issues. Also, the packaging remains the main issue for
combining MEMS and SoC together for new low-power and
ultra miniaturized systems. It is the believe of CSEM that the
Integrated Systems for Information Technology platform is
well armed to face and solve these important challenges!
23

Data Fusion for Wireless Distributed Tracking Systems
F. Rampogna, P.-A. Beuchat, A. Brenzikofer, D. Beyeler, E. Franzi, E. Grenet, A. Hutter, P. Nussbaum, L. Von Allmen
The objective of this work is to perform the fusion of data gathered from distributed movement tracking 2D/3D camera nodes and to provide the
user with a unified and synthetic view of the activity in the area being monitored. The data communication between the various embedded slave
tracking nodes and the master node is performed either through a low-power, low-data-rate, 2.4 GHz RF ad-hoc network, using a portion of the
IEEE8102.15.4 TDMA protocol, or through an emulation of the radio network over a wired ethernet link, for test and debug purposes.
The work in this project has been done within the RISE multidisciplinary
project framework [1] .
Both the 2D/3D tracking camera node, and the master node
are implemented using CSEM DEVISE cameras [2] . They are
based on a 500 MHz BF533 DSP/MCU, and implement
32 MiBytes SDRAM, 2 MiBytes FLASH memory, a 2.4 GHz
RF transceiver, a 100 Mbit/s ethernet interface, and a TCP/IP
protocol stack developed in-house. The 2D camera nodes use
CSEM vision sensors [3] , and the 3D camera nodes, MESA’s
3D imagers [4] .
Figure 1: Principles of data fusion using three 2D camera nodes
Figure 1 shows an example of a room being monitored.
Various people are present in the room, some are seated,
others are walking, and others are discussing while standing
still. Three 2D tracking nodes are installed at the ceiling level
and are looking down. They have three different orientations:
node 1 is oriented towards the west, node 2 towards the north
and node 3 towards the east. They all have the same fish-eye
optical characteristics. Each camera node detects the
presence and tracks the movement of objects in its own field
of view (FOV). For each tracked object in the FOV, the
following nature of each object is extracted:
• Unknown (U): the object characteristics are such that it is
impossible to determine what kind of object is detected
• Human (H): the presence of a person has been detected
• Group (GN): the presence of two or more people has been
detected
By knowing both the spatial location, optical characteristics,
orientation and height of each camera node, it is possible to
project the pixel coordinates corresponding to the position of
24
the feet of the tracked object, first to a local metric coordinates
space, and then, to a unified metric room coordinates space.
In order to cover a large floor-level area, very wide angle
lenses are typically used in 2D camera nodes. These lenses
greatly distort the image and therefore a geometric correction
is required in order to perform an accurate floor-level
projection of the positions of tracked objects.
Once the coordinates of all the objects being tracked by all the
nodes have been unified, a data fusion algorithm groups
together the objects which are spatially close-enough, and
associates to them extended properties, such as their kind: U,
H, G1 to Gn. If 3D camera nodes are used for the monitoring,
the height of tracked objects will also be displayed.
Camera node #1 (2D) Camera node #2 (2D) Camera node #3 (2D) Camera node #4 (3D)
1 2 3 4
Unified coordinates view of detected objects Synthetic view after data fusion
Figure 2: Example of monitored room (CSEM main entrance)
Figure 2 illustrates an example of data fusion obtained from
the monitoring of the CSEM’s main building entrance, where
one person is currently leaving the building. The contrast edge
images as seen by the three 2D vision sensor nodes and the
image heights seen by the 3D camera node are displayed.
The unified coordinates representation of the objects seen by
the various camera nodes is shown at the bottom left, together
with their respective trajectories and the representation of the
cameras FOV. The synthetic representation of the objects
tracked by the cameras after data fusion is shown at the
bottom right, together with the location and orientation of the
various camera nodes.
[1] A. Hutter, et al., “RISE – The Rich Sensing Concept”, in this
report, page 15
[2] www.csem-devise.com
[3] www.csem-devise.com/Vision-MD535V2A1-413-09-06.pdf
[4] www.mesa-imaging.ch

High Dynamic Range Versatile Front-End for Vision Systems
P. Heim, F. Kaess, P.-F. Rüedi
A 128 by 152 pixel array with very high intra-scene dynamic range has been integrated in a 0.18 µm optical process. It features a data
representation which encodes nearly 7 decades of illumination with a 10 bit data word. Furthermore, the data representation used facilitates
subsequent data processing such as contrast computation.
There is an increasing need for optical sensors optimally
suited for systems whose purpose is not to restitute an image
to a final user, but to analyze the content of a visual scene
and make a decision. The main requirements for such a
sensor are a wide intra-scene dynamic range and a data
representation facilitating processing. Standard image sensors
have a too narrow dynamic range to cope with the
tremendous change of illumination occurring in natural visual
scenes. Logarithmic imagers offer a wide dynamic range and
a data representation which easily discard illumination
changes in an image. However, up to now, the logarithmic
compression has been performed in the analog domain,
bringing a high pixel-to-pixel fixed pattern noise, which makes
them unusable for commercial applications.
The visual front-end developed at CSEM circumvents this
issue. It incorporates a high dynamic range pixel array with
logarithmic compression in the digital domain to avoid the
large fixed pattern noise associated with analog compression.
Figure 1 shows a block diagram of a pixel and the logarithmic
time generator. Each pixel integrates the photocurrent
delivered by a photodiode on a capacitor. The resulting
voltage is continuously compared to a reference voltage
(VREF). Once VREF is reached, the content of a 10-bit digital
word distributed to all pixels in parallel is stored in the pixel
memory. This digital word evolves over time to code the
logarithm of the time elapsed since the beginning of the
integration. Once photo-current integration is terminated, the
10-bit words stored in the pixel array are read-out.
Figure 1: Block diagram of the pixel and logarithmic time generator
The data representation delivered by the sensor enables to
easily discard illumination and compute the contrast between
neighbouring pixels.
The circuit encompasses an array of 128 by 152 pixels, with a
pixel pitch of 14 µm and a fill factor of 20% in a 0.18 µm
optical process. Figure 2 shows a microphotograph of the
circuit.
Figure 2: Micrograph of the circuit
The left of Figure 3 shows an image acquired with the sensor.
Notice that the face of the person and the outside background
are simultaneously visible, illustrating the high dynamic range.
The right of Figure 3 shows the contrast representation
obtained by simply computing the difference between
neighboring pixels. Notice the independence on the
illumination level.
Figure 3: High dynamic range visual scene
A system-on-chip [1] incorporating a 320 by 240 (QVGA) pixel
array based on this principle, an icyflex [2] processor, RAM and
communication interfaces is now in the process of being
integrated. It will enable vision applications (image capture
and processing) to be performed on a single chip.
[1] C. Arm, et al., “icycam , a System-On-Chip (SoC) for Vision
Applications”, in this report, page 30
[2] M. Morgan, et al., “icyflex, a Low Power 32-bit Microcontroller
Core”, CSEM Scientific and Technical Report 2006, page 20
25

A High-Performance 2.4 GHz RF Front-End in a 90 nm Process
M. Kucera, N. Scolari, F. Pengg, P. Persechini , D. Ruffieux, A. Vouilloz, E. Vardarli, P. Ferrat, J. Chabloz, R. Caseiro, C. Monneron
The ever ongoing advances in semiconductor manufacturing and the continuous shrink of the integrated transistors pose new challenges and
require innovative solutions for the design of high-performance and low-power RF circuits in the ultra-deep submicron range. This paper provides
insight in the design of a high performance 2.4 GHz RF front-end in 90 nm CMOS.
The well known “Moore’s Law” has been valid for nearly 40
years, confirming that integrated circuit (IC) technology
evolves every 18 months with a new process generation that
enables higher circuit integration and reduced IC size and
cost. While the main driving forces are large digital ICs,
analog and RF circuits can also benefit from these technology
advances, in particular system-on-chip (SoC) realizations
where they are embedded jointly with large digital sections
(e.g. mobile telephony ICs).
Concerning radio SoCs, the co-integration of highperformance
low-power RF circuits together with digital blocks
has been proven using submicron CMOS
(0.5µm - 0.18µm) [1] . RF-platforms of the next generation,
such as Software Defined Radios (SDR), rely heavily on large
digital processing blocks [2] , which pleads for using ultra-deep
submicron (UDSM) CMOS (90 nm and beyond). The
challenge today thus consists of the design of highperformance
RF circuits with competitive sizes of the RF
blocks (UDSM CMOS being expensive) and with low power
consumption, which is critical for portable, battery operated
applications targeted by CSEM.
Within this context, CSEM has designed a 90 nm CMOS RF
front-end circuit with the following goals:
• To achieve high-performance specifications with lowest
possible power consumption while minimizing the required
silicon area.
• To design in a standard digital 90 nm CMOS process,
without relying on costly RF/analog processing options:
this is mandatory for enabling seamless co-integration
with digital circuits.
• To establish a library of optimized RF passive devices: the
generic RF passive devices (inductors, capacitors,
varicaps, etc) provided by silicon foundries usually have
inadequate performance and prohibitive sizes, or require
additional processing options. The design of optimized
passives on the standard digital technology is crucial for
achieving best-in-class RF performance.
The RF front-end targets the 2.4 GHz ISM band, and includes
a receiver front-end (LNA, down-conversion mixers), a
transmitter front-end (PA, up-conversion mixers), and the
critical blocks of the frequency synthesizer (RF VCO, LO
buffers, pre-scalers and multi-modulus dividers). The target
specifications are a noise figure of 2 dB for the receiver frontend
with high linearity (IIP3 up to -13 dBm for an entire
receiver), and a current consumption of 8 mA from a 1.6 V
supply. The transmitter targets +27 dBm of output power
which requires the handling of about 1 W and 500 mA on-chip.
The layout of the RF front-end IC is shown in Figure 1.
26
Figure 1: Layout of the 2.4 GHz RF front–end in 90nm CMOS
As mentioned above, special care was taken in the design
and modelling of dedicated passives using the methodology
developed at CSEM [3] . A close-up view of one of the RF
inductors together with its RF test-fixture is given in Figure 2.
An inductance value of 12 nH and a quality factor Q better
than 10 at 2.4 GHz are expected. It occupies a surface of
200x200 µm 2 (in the foundry design kit, no inductances were
available without using RF options and limited metal layers).
Figure 2: Layout of an inductor in 90nm (right) with the pad structure
for the device measurement on the RF prober (left)
The 2.4GHz RF front-end presented in this paper is currently
in fabrication and samples for characterization are expected
shortly.
[1] V. Peiris, et al., “A 1V 433/868MHz 25kb/s-FSK 2kb/s-OOK RF
Transceiver SoC in Standard Digital 0.18 μm CMOS,” in Int.
Solid-State Circ. Conf. Dig. of Tech. Papers, Feb. 2005,
258–259.
[2] E. Le Roux, “Low Power Flexible Digital Demodulator for
Integrated RF Transceiver”, CSEM Scientific and Technical
Report 2006, page 27
[3] F. Giroud, et al., “Integrated Inductors in 0.18 μm CMOS and
Model-Fitting Approach for Low-power 2.45GHz RF blocks”,
CSEM Scientific and Technical Report 2005, page 23

Direct Modulation RF Transmitter and Super-Heterodyne Low-IF Receiver Development
Platform for 868 MHz and 915 MHz ISM Bands
M. Contaldo, E. Le Roux, D. Ruffieux, P. Volet, M. Kucera, N. Raemy, F. Giroud, F. Pengg, S. Gyger, C. Arm, P. Heim, F. Kaess,
V. Peiris
This paper presents the design of a radio development platform suited for developing ultra low-power high-performance narrow-band RF
transceivers. In particular, this platform will be used for validating an 868 MHz/915 MHz RF IC featuring up to ±200kHz modulation bandwidth for
different constant-envelope modulation schemes, and consuming below 3 mA current in receive mode under a very-low 1 V supply.
For wireless sensor networks or body-area networks for biomedical
and lifestyle applications, the need of a miniature and
ultra-low power radio transceiver is mandatory to achieve
multi-year autonomy with un-obtrusive embodiment.
Ultra low-power consumption (below 3 mA under 1 V supply in
receive mode) has been demonstrated for radios operating in
sub-GHz bands and using simple FSK/OOK modulation
schemes [1] . On the other hand, the requirements in terms of
modulation schemes and bandwidths happen to differ
significantly depending on the targeted applications. The
design of an optimal radio architecture remains thus a
complex task as the impact and the added value of various
modulation strategies must be quantified carefully before final
integration, in particular for low-power radios.
Although high- and low-level simulations help for preliminary
validation, a given radio architecture may be fully validated
only with real-world measurements including complex channel
and interference situations which are difficult to simulate. To
address this issue, this paper presents an intermediate
approach, in the form of a microelectronics-oriented hardware
development platform, as depicted in Figure 1.
Figure 1: Development platform block diagram
This approach with a programmable FPGA-based back-end
enables the development and validation of various modulation
schemes with a high degree of flexibility, by programming
baseband processing algorithms into the FPGA, and
characterizing the link performance before full integration.
Because the front-end is a low-power RF IC, the architecture
of the platform is very close to that of an integrated circuit.
Hence the design of a complete transceiver combining both
sections on a single die will be enabled with a low risk level.
The RF front-end IC includes the transmitter (Tx), receiver
(Rx) and frequency synthesizer (PLL) circuitry, from the
antenna input towards the analog baseband, without relying
on any other external active components. The Rx/Tx is
designed for operation in the 868/915 MHz bands. The FPGA
embeds the digital parts such as the modulation/demodulation
section of the radio, the control for the RF front-end IC and the
interfaces. For the slow digital configuration signals, e.g.
analog sub-block bias settings, the configuration is done
through serial link (I2C). For fast digital signal, i.e. the RF
synthesizer settings, the configuration is done through a
parallel bus. The FPGA clock signal is generated on the RF
front-end IC, therefore their association does not need any
additional circuit.
Within the RF front-end IC, the transmitter is based on a direct
modulation architecture. The frequency synthesizer is
implemented by means of a fractional-N PLL employing a
3rd order MASH sigma delta modulator, taking advantage of its
beneficial noise shaping effect. The external loop filter and the
programmable charge pump permit a good customizability of
the synthesizer performances. The synthesized signal is then
directly coupled to the power amplifier and directed to a SAW
filter, before reaching the antenna. The receiver is based on a
heterodyne low-IF architecture that down-converts the RF
signal into at 96-103 MHz intermediate frequency and then to
75-150 kHz, where it can be filtered. The signal is then
converted in the digital domain using an integrated
phase-ADC whose output drives the FPGA to allow the design
and measurement of different demodulations [2]
The main specifications of the radio are up to ±200 kHz
modulation bandwidth, with a 3 mA current consumption in Rx
for -105 dBm sensitivity, and 40 mA in Tx for a 10 dBm output
power, under 1V supply. A photograph of the RF front-end IC,
integrated in 0.18um CMOS, is given in Figure 2.
Figure 2: Microphotograph of the RF front-end IC
[1] V. Peiris, et al., “A 1V 433/868MHz 25kb/s-FSK 2kb/s-OOK RF
Transceiver SoC in Standard Digital 0.18 μm CMOS,” in Int.
Solid-State Circ. Conf. Dig. of Tech. Papers, Feb. 2005, 258-259
[2] E. Le Roux, “Low Power Flexible Digital Demodulator for
Integrated RF Transceiver”, CSEM Scientific and Technical
Report 2006, page 27
27

Quasi-Harmonic Quadrature CMOS Relaxation Oscillator
J. Chabloz, D. Ruffieux
In this paper, a solution to realize a local oscillator (LO) for a low power super-heterodyne receiver is presented. The complete local frequency
synthesis solution comprises a fixed-frequency bulk-acoustic wave (BAW) RF oscillator with low phase noise and low tuning range.
A quasi-harmonic quadrature relaxation oscillator with a large tuning range is realized and can be used to compensate for variations in the
RF oscillator as well as to cover the entire bandwidth for multiple channel selection.
The receiver for which the presented oscillator is specifically
designed is based on a super-heterodyne architecture and its
block schematic is described in Figure 1. The receiver frontend
and baseband parts have already been integrated and
characterized with external oscillators [1] . A BAW oscillator
embedded within a digital frequency synthesis [2] is used as a
first local source (BAW RF LO) and runs at a fixed frequency,
determined by the physical dimensions of the BAW resonator.
The second downconversion uses a quadrature relaxation
oscillator (IF LO) with a large tuning range [3] that is presented
below.
28
Passband
Balun
BAW
Filter
2400.0 - 2483.5 MHz
On-chip
LNA
2330.0 MHz
fixed
BAW
LO
IF Amplifier
Quadrature
IF Oscill.
Frequency Synthesis
Figure 1: Super-heterodyne receiver architecture
70.0 - 153.5 MHz
tunable
Since the second downconversion is direct, the selected
channel frequency is determined by the sum or the difference
of both oscillator frequencies. Therefore the allowed frequency
excursion on the second oscillator allows to compensate
entirely for the lack of tunability of the first one.
The proposed quasi-harmonic quadrature relaxation oscillator
architecture is described in Figure 2. Coupling transistors are
used to couple two classical relaxation oscillator cores.
Coupling
transistors
M3
M1
M2
Figure 2: Quadrature oscillator architecture
The wide variation of bias current needed to tune the
oscillation frequency over the required range also creates
wide variations in the oscillator operating point, more
specifically in the steady-state oscillation amplitude. In order
to increase the tuning range, linearize the current-to-frequency
characteristic and allow the oscillator to stay in the quasiharmonic
mode over the entire range, an amplitude control
has been designed.
The presented circuit has been fabricated in a standard
0.18 µm CMOS process. Figure 3 shows the actual receiver
test chip photograph. The BAW resonator is bonded together
with the chip.
Figure 3: Receiver test chip photograph
The oscillation frequency has been measured with different
amplitude settings and the results are shown in Figure 4. It
can be seen that the tuning range covers the wanted
frequencies which range from 70 MHz to 150 MHz.
Oscillation frequency [MHz]
150
140
130
120
110
100
90
80
70
60 0
120
140
1
160
2
180
3
200
Relaxation oscillator current consumption (wo buffer) [μA]
4
220
5
240
6
K = 1.35
K = 1.2
Figure 4: Measured oscillator frequency tuning range with two
different amplitude settings
The quadrature coupling principle is verified by measuring an
average phase difference of 89° between the I and Q signals.
Spot phase noises of -104 dBc/Hz at 1 MHz offset and
-111 dBc/Hz at 3 MHz offset have been measured.
[1] J. Chabloz, et al., “A Low-Power 2.4GHz CMOS Front-End using
BAW Resonators”, ISSCC’06 proceedings, 1244-1253
[2] D. Ruffieux, et al., “An Agile 2.4GHz MEMS-Based Digital
Frequency Synthesizer”, CSEM Scientific and Technical Report
2006, page 24
[3] J. Chabloz, et al., “Frequency Synthesis for a Low-Power
2.4GHz Receiver using a BAW Oscillator and a Relaxation
Oscillator”, ESSCIRC’07 proceedings, 492-495
260
7
280

Silicon Resonators: Thermal Compensation and Q Factor Optimization
J. Baborowski, A.Pezous, C. Muller, Y. Welte, M.-A. Dubois
The feasibility of two families of AlN/Si resonators has been demonstrated. The resonating structure is obtained with silicon suspended beams
driven by an AlN piezoelectric layer. The flexural resonators exhibit extremely low thermal drift of resonance frequency (α close to zero). The
thermal compensation has been obtained at device-level by using SiO2 with an appropriate thickness. The extensional resonators exhibit a Q factor
larger than 140 000 below 1 mbar and a coupling coefficient of 0.05%.
High Q silicon MEMS resonators have great potential for onchip
high frequency synthesis, integrated circuit clock
generation, and other applications based on a stable
frequency reference signal. The thermal compensation of the
silicon resonators as well as the development of miniature
inexpensive lead-free packaging solutions, represent however
real technical and scientific challenges.
CSEM SA has demonstrated the feasibility of two types of
AlN/Si resonators [1] :
• Thermally compensated, 20 kHz to 140 kHz flexural outof-plane
mode resonator,
• High Q, 1 MHz extensional in-plane mode resonator.
Both types of resonators are currently being implemented in
the 2.4 GHz MEMS-based ULP transceiver.
Figure 1: Top view of 32kHz silicon resonator with AlN actuation
The triple tuning fork out-of-plane resonator (Figure 1)
presents a zero first order Thermal Coefficient of frequency (α
TCf) that has been obtained at the device level by balancing
the negative Thermal Coefficient of Elasticity (TCE) of Si and
AlN with the positive TCE of SiO2. The frequency stability over
a temperature range from 0° to +60°C is better than 20 ppm
at 70 kHz. The possibility of fine tuning the TCf by trimming
the thickness of SiO2 has been shown, as well as the ability to
adjust the resonance frequency by applying a DC bias, with a
sensitivity of 0.3 ppm/V.
Finite element modelling has been used to analyze the
distribution of energy in the tuning fork. It has been shown that
the clamping conditions between the vibrating arms and bulk
substrate are the major source of energy loss (Figure 2). A
new design has been realized to reduce this energy leakage
and hence increase the Q factor.
In the case of the 1MHz extensional mode resonators, the
effect of air pressure has been measured. In order to obtain
stable values of Q factors higher than 100000 it is mandatory
to maintain the resonator at a pressure below 1 mbar
(Figure 3). This type of resonator exhibits a Q factor in
vacuum as high as 140000, a coupling factor k 2 eff of 0.05%, a
motional resistance below 200 Ohm and a mainly linear TCf of
-28.5 ppm/°C. The tolerance of the resonance frequency over
100 mm wafer is lower than 0.1%.
Figure 2: FEM simulation of the energy distribution in tuning fork
Hermetic packaging at low pressure is one of the largest
barriers to commercialisation of MEMS timing reference. In
this project the solutions for packaging the backside of the
resonator have been demonstrated. The first solution consists
in the fabrication of buried cavities within the SOI wafer,
followed by the building of the piezoelectric resonator directly
on the membrane. The second solution uses a capping wafer
(thin silicon or Pyrex) sealed by low temperature fusion
bonding or by anodic bonding [2] .
Figure 3: Variation of Q factor as function of pressure for 1MHz
extensional resonator
[1] J. Baborowski, C. Bourgeois, A. Pezous, C. Muller,
M.-A. Dubois, Piezoelectrically Activated Silicon Resonators,
Proceedings of the Joint 2007 European Frequency and Time
Forum & 2007 IEEE Frequency Control Symposium, 1210-1213
[2] D. Ruffieux, et al., “PackTime – Zero-Level Packaging of Silicon
Time-base”, in this report, page 16
29

icycam, a System-On Chip (SoC) for Vision Applications
C. Arm, R. Caseiro, S. Gyger, P. Heim, F. Kaess, J.-L. Nagel, P.-F. Rüedi, S. Todeschini
Icycam is a circuit combining on the same chip a 32-bit icyflex [1] processor operated at 50 MIPS, and a high dynamic range versatile pixel array,
integrated on a 0.18 μm optical process. It enables the implementation on a single chip of image capture and processing, thus bringing
considerable advantages in terms of cost, size and power consumption.
There is a high demand for low cost and low power vision
systems able to perform real-time analysis of a visual scene.
Merging on a single chip a pixel array to capture an image and
a processor to analyze it offers interesting perspectives in
terms of cost and power consumption reduction.
Icycam has been developed to address vision tasks in fields
such as surveillance, automotive, optical character recognition
and industrial control. It incorporates a high dynamic range
pixel array [2] , an icyflex [1] processor, RAM and digital
peripherals to enable a maximum of flexibility. It can be
programmed in assembler or C code to implement vision
algorithms and controlling tasks.
The icycam chip architecture is illustrated on Figure 1 and
detailed in the following sections.
30
RAM
128 KiBytes
SPI1
SPI2
320 x 240 (QVGA)
high dynamic range
versatile pixel array
Sensor interface
GPIO
64
PPI
Figure 1: icycam chip architecture
SDRAM
GPU
icyflex
UART
JTAG
The heart of the system is the 32-bit icyflex processor clocked
at a 50 MHz frequency. It communicates with the pixel array,
the on-chip SRAM and peripherals via a 64-bit internal data
bus.
The pixel array has a resolution of 320 by 240 pixels (QVGA),
with a pixel pitch of 14 µm. Its digital-domain pixel-level
logarithmic compression makes it a low noise logarithmic
sensor with close to 7 decades of intra-scene dynamic range
encoded on a 10-bit data word. Two special purpose
interfaces are implemented to pre-process the data flow
coming out from the pixel array. The first one is a column-level
16-bit accumulator allowing to sum a row of pixels in one clock
cycle, for example to average a group of rows for 1-D
applications. The second one is able to extract on the fly the
local contrast direction and magnitude (relative change of
illumination between neighbouring pixels) when data is
transferred from the pixel array to the memory. Thus it offers a
data representation facilitating image analysis, without the
overhead in terms of processing time.
Data transfer between the pixel array and memory or
peripherals is performed by a group of 4 (10 bits per pixel) or
a 8 (8 bits per pixel) pixels in parallel at system clock rate.
This image data can be processed with the icyflex’s Data
Processing Unit (DPU) which has been complemented with a
Graphical Processing Unit (GPU) tailored for vision
algorithms, able to perform simple arithmetical operations on
8- or 16-bit data grouped in a 64-bit word.
Internal SRAM being size consuming, the internal data and
program memory space is limited to 128 KiBytes. This
memory range can be extended with an external SDRAM up
to 32 MiBytes. The whole memory space is unified which
means it is accessible via the data, program and DMA busses.
An internal DMA working on 8/16/32 and 64 bits enables
transfers from/to the vision sensor, memories and peripherals
with data packing and unpacking features. The DMA has a
2 dimensional transfer mode for the source as well as the
destination addresses which is a prerequisite for vision
applications.
A parallel peripheral interface (PPI) is incorporated to enable
data transfer to an external DSP for vision applications
requiring more processing power than that available on-chip.
This PPI port also enables the coupling of an external sensor,
such as a high resolution colour imager, to icycam.
To further improve flexibility and ease of use, SPI, UART,
GPIO and JTAG interfaces are also implemented on icycam.
This wide range of interfaces makes icycam a truly versatile
circuit. When the limited amount of on-chip memory and
processing power is sufficient, it can be used as a single chip
solution. When a high amount of data has to be processed it
can be used with an external memory. Finally, if a high
processing power is required, it can be used as a sensor
connected to an external DSP.
The chip is in the process of being integrated in a 0.18 µm
optical technology. It incorporates all the necessary test
hardware in order to be easily testable in production.
[1] M. Morgan, et al., “icyflex – A Low Power 32-bit Microcontroller
Core”, CSEM Scientific and Technical Report 2006, page 20
[2] P. Heim, et al., “High dynamic range versatile front-end for vision
systems”, in this report, page 25

Programmable Multi-Processor Engine for Ultra-Low-Power Single-Chip DVB Receiver
C. Arm, P.-D. Pfister, F. Rampogna, Ch. Ruppert • , A. Duret •
A family of System-On-Chip (SoC) circuits implementing terrestrial mobile digital TV (DVB-T/H) receivers as single-die solutions requiring very few
external components has been developed and is being produced by the industrial partner of this project. The use of ultra-low-power programmable
DSPs for the implementation of the Orthogonal Frequency Division Multiplex (OFDM) demodulation and adaptive channel estimation/correction
allows an automatic adaptation of the receiver to the fast-changing reception conditions encountered in mobile receivers
CSEM is participating in a CTI/KTI project whose goal is to
develop modem core intellectual property (IP) supporting
multiple broadband wireless OFDM modulations (DAB, DVB,
T-DMB, MediaFlo, etc.). The core is architectured as a
software defined radio implementing a multiprocessor
architecture based on CSEM Macgic ® DSP core [1] .
The final goal for the industrial partner [2] of this project is the
production of a family of low-cost, low voltage, ultra-low power
single-die digital television receivers in advanced CMOS
technologies (90 nm and smaller geometries). The first
member of this family is the AS-101, which targets the
following ETSI [3] standards:
• DVB-T, Digital Video Broadcasting for low-power
terrestrial digital television receivers
• DVB-H, for mobile ultra-low-power multimedia receivers.
The low power consumption, of less than 325 mW for DVB-T
reception, together with the small footprint, less than 100 mm2 for a complete module, a very short bill of material, and a
choice of standard host interfaces (USB2.0, SDIO, SPI) make
them ideal for a very wide range of mobile consumer
applications.
The structure of the AS-101 DVB receiver chip is shown in
Figure 1. The circuit implements a multiband zero
intermediate frequency RF-tuner, the reprogrammable OFDM
engine made of multiple Macgic ® DSP cores and hardware
accelerators, the channel decoding and the link layer data
stream extraction using a standard 32-bit processor core
together with error correction hardware accelerators.
Figure 1: AS-101 Single-die 90 nm DVB-T/H receiver structure
Two other circuits are members of this family of low-power
OFDM receivers: the AS-102 limited to the support of the
DVB-T standard, and the AS-103 which improves the
reception in difficult conditions by allowing antenna (spatial)
diversity (use of multiple reception antennas).
The CSEM has developed the Macgic ® DSP architecture. The
DSP has been specially tailored and optimized to best suit
OFDM demodulation and channel estimation/correction
algorithms. New instructions and specific operations have
been added; some others, irrelevant to the targeted
application, removed from the instruction set, so as to
optimise its speed and energy consumption.
The software defined radio technology (SDR) architecture,
based on the Macgic ® cores, is a key element of ensuring
quality of service. In addition, the flexibility of CSEM
programmable technology allows adaptive data processing to
therefore guarantee the best performance in all reception
conditions. Our innovative DSP based approach provides the
flexibility to select the most appropriate algorithm in many
circumstances and conditions, and in particular to recover
weak signals in a noisy environment or compensate for the
Doppler effect.
Adaptive channel correction algorithms have been devised
and implemented. These algorithms improve the
demodulation signal-to-noise ratio and therefore reduce the bit
error rate under the most common adverse mobile reception
conditions:
• Multipath: Single-frequency networks where more than
one transmitter broadcasts the same stream, and/or
multiple electromagnetic obstacles/mirrors such as
buildings (and walls/windows when used indoors) that
scatter and/or reflect the broadcast signal, may lead to
potentially destructive interferences, depending on the
spatial location of the receiver. Such interferences can be
countered through antenna diversity.
• Fast changing reception conditions caused by moving
receiver or obstacles, which are typical in urban areas.
• Doppler effect that is caused by fast-moving objects:
typically a mobile receiver located in a car/train.
Prototypes and demonstrators have been developed and have
been available for more than one year. The AS-101 circuit has
entered the production stage and has already been licensed
to a few customers of the industrial partner.
The project partners are Abilis Systems and HEIG-VD [4] .
This work was partly funded by the CTI/KTI which CSEM
thanks.
•
Abilis Systems
[1] F. Rampogna, et al., “FPGA Prototyping Platform for the
Macgic DSP Cores”, CSEM Scientific and Technical Report
2003, page 27
[2] www.Abiliss.com
[3] www.etsi.org/WebSite/Technologies/DVB.aspx
[4] www.heig-vd.ch
31

PHOTONICS
Nicolas Blanc
The Photonics Division has over the last few years enjoyed a
steady growth in terms of income, number of employees and
technologies. To further sustain and reinforce CSEM activity in
this domain, major decisions were taken at the end of 2006
with a strong impact on key changes in the Photonics Division.
Firstly, the two sections “Image Sensing” and “Optoelectronics
Systems” moved in September 2007 from the Badenerstrasse
to its new site in Technopark Zürich, where CSEM Zurich
rents 1’1000 m2 . The completely new and modern
infrastructure includes several hundred m2 of lab space,
mostly optical labs with conditioned and filtered air. CSEM
Zurich benefits now from a very central location with excellent
public transport: Zurich main railway station is within
10 minutes and Zurich airport can be reached within
20 minutes by train. Moreover the new location offers many
potential synergies with nearby small- and medium-size
companies, including numerous start-ups and high-tech
corporations.
Secondly, the two sections “Micro-optical Systems” and
“Polymer Optoelectronics” moved in January 2008 to Basel to
build-up a new Division entitled “Functional Coatings”. This
Division is located in the Areal Rosental and will further
develop technologies related to passive (e.g. micro-optical
elements and optical security devices) as well as active (e.g.
polymer light-emitting devices, PLEDs) opto-electronics
components and systems, with a focus on organic materials
and moulding, embossing, as well as various printing
processes. The Functional Coatings Division benefits from
important investments including 500 m2 of fully equipped
clean rooms. CSEM presence in Basel is also expected to
significantly reinforce its R&D activity, in particular for
applications in the domain of Life Science, Chemistry and
Pharmaceutics.
On the scientific and technical side, the Photonics Division in
2007 kept its focus on the development of optoelectronic
components, including PLEDs, micro-optical elements and
image sensors, as well as their combination in highly
integrated and compact systems. One strategic axis remains
with the development of novel devices on the basis of polymer
materials which can be very advantageous in terms of costs
and for applications requiring large area devices. This is
notably achieved thanks to the use of low cost manufacturing
processes derived from the printing industry. In this field the
material properties and formulation are key to the
development and optimization of state-of-the art polymer
based optoelectronics components. In order to speed up the
screening and formulation of solvent processed organic LEDs,
a modified pipetting-robot together with an automated optoelectrical
characterization system have been developed. This
high-throughput apparatus allows the fabrication and
characterization of batches of 49 PLED samples in one
experimental run, enabling thus the systematic study of the
influence of parameter variations to the overall device
performances and providing extensive datasets for material
testing, device optimization and device modelling. A
concentration sweep of individual blend components can for
example quickly reveal the ideal blend ratio for optimum
composition.
3D-cameras based on the Time-of-Flight principle are able to
provide depth maps of their environment in real-time. Different
modulation schemes from continuous wave modulation,
pulsed mode and more complex modulations schemes can be
used as well. In all cases the 3D camera relies on an active
illumination that can be intensity modulated at high frequency.
Alternatively the detailed imaging of fast moving objects
(> 100 m/s) also calls for flash light illumination. For such
applications a new illumination unit has been realized based
on multi-mode vertical-cavity surface-emitting laser arrays.
This approach reaches modulation frequencies of up to
80 MHz and an optical peak output power of 1.3 Watt.
Miniaturization and low-power are two key characteristics of
CSEM heritage and these characteristics are reflected in
many projects. As an example within the European project
MuFly, CSEM has developed a miniaturized and light weight
360° camera module for autonomous micro aerial vehicles.
The camera fulfils stringent requirements: a power
consumption of less than 1 mW, a weight of less than 5 g and
small dimensions of ~2 cm3 , while providing a high dynamic
range in excess of 140 dB for reliable indoor and outdoor
operations under various illumination conditions. A further
example of miniaturization is provided in the development of a
highly integrated optical linear. The latter is designed to fit in a
volume of only 50 mm3 while providing spatial resolution in the
100 nm range at a speed of up to 5 m/s. This is achieved
thanks to a dedicated custom image sensor, a folded
telecentric optics manufactured by injection moulding and
further SMD components including a LED illumination and
passive elements, all components being mounted on one
single flexible print.
Last but not least CSEM has built up its capability in the
testing and qualification of integrated circuits and optical
sensors for small volume series. The testing of a circuit is an
essential but also quite an expensive step in the production
flow of semiconductor devices. Frequently CSEM customers
are looking for small volume production of components with
very high expectations with respect to quality. A testing
environment has thus been set up to support such production
verification and qualification in-house ensuring very short
qualification time after prototype evaluation. This is part of the
new offering of CSEM and in particular the Photonics Division
to its partners and customers.
33

Miniaturized 360°-Camera Module for Collision Avoidance
P. Ferrat, C. Gimkiewicz, S. Neukom, Y. Zha, A. Brenzikofer, T. Baechler
Omni-view cameras for autonomous micro aerial vehicles have to fulfil stringent requirements: low power consumption (< 1 mW), low weight
(< 5 g), small dimensions (~ 2 cm 3 ), and a high dynamic range (> 140 dB) for reliable indoor and outdoor operations under various illumination
conditions.
The presented 360°-vision ultra-miniature camera platform
(Figure 1) is based on two components: a catadioptric lens
system and a dedicated image sensor. The optical system
consists of a hyperbolic mirror and an imaging lens (Figure 2).
The vertical field of view is +10° to -35°.
Figure 1: Picture of the complete camera module
The CMOS image sensor (Figure 3) provides a polar pixel
field with 128 (polar) by 64 (radial) pixels. Since the number of
pixels for each circle is constant, the unwrapped panoramic
image achieves a constant resolution for all image regions.
The whole camera module delivers 40 frames per second and
includes an optical image preprocessing for an effortless remapping
of the acquired image into undistorted cylindrical
coordinates.
Figure 2: Schematics drawing of the optical sub-system when used
for triangulation
Figure 3: Layout of the image sensor
The very high dynamic range is achieved by the ProgLog
pixel implemented on the image sensor. For low optical input
34
power the pixel has a linear response, whereas for high
optical input power the pixel shows a logarithmic behaviour.
The kneepoint between linear and logarithmic behaviour can
be set by applying an external voltage to the pin VLOG.
Triangulation with omni-view cameras
Especially for flying robots, fast object recognition and
collision avoidance has to be ensured. Here, the application of
an active triangulation system is proposed (Figure 2). A laser
module is mounted on top of the omni-view camera. The laser
emits a 360° laser plane. The reflections of the laser plane on
objects in a room form a distorted circle, where the distortion
is a measure for the object distance. Figure 4 shows the
calculated distance resolution for objects closer than 3 m. The
resolution can be increased by various means if required. The
plot in Figure 4 is computed for a distance of the laser to the
0° axis of 150 mm and a laser beam angle of 8˚ (Figure 4).
Figure 4: Distance resolution of the optical sub-system shown in
Figure 2.
Stereo vision omni-view camera system
Placing one camera up-side-down onto another one increases
the vertical field of view to -35° to + 35°. The overlapping area
(-10° to +10°) allows a stereo view of the captured objects. To
calculate the distance D to the objects, the object ray angles
of both cameras (α1 and α2) are combined with the distance
Dcam between the optical axes of the two cameras:
D cam
D =
tan (α 1)
+ tan(α
2 )
Conclusion
The presented camera module can be used in many different
areas, but ideally in applications needing instantaneous omnidirectional
view including distance information. Possible
application fields are: Automotive, Surveillance and Security,
Robotics, Navigation and Collision Avoidance.
The Mufly project has been supported by the 6 th Framework
Program of the European Commission contract number FP6-
IST-034120, Action line: Cognitive Systems.

Optoelectronic Test Equipment for Image Sensors and Systems Qualification
A. Baumgartner
The testing of a circuit is an essential but quite expensive step in the production flow of semiconductor devices. Frequently CSEM customers are
looking for small volume production with a high quality level. Therefore a testing environment has been set up to support production verification and
qualification in-house with moderate investments and in a very short time after prototype evaluation. This is achieved thanks to the development of
very similar routines for both evaluation measurements at the prototype level and for production verification.
Following the evaluation of the first prototypes, the set-up of a
fully automatic test system for production testing typically
requires a large effort and high investments.
Quite often for products resulting from “leading edge” research
projects, the standard industry levels of quality are expected
but for significantly lower quantities. Furthermore the
development of test plans for automatic test equipments
(ATE) can be quite costly due to the high time pressure for
rapid development cycles and a quick ramp up of the
production.
Prototype evaluation is a key phase in the development of
novel image sensors. This evaluation can be very timeconsuming
and needs to be repeated for each new sensor
circuit. The measurements done during evaluation are similar
to the testing cycles for the production verification. For largevolume
production, testing is normally done on dedicated test
systems. In this project, a cost-effective evaluation system for
production testing was investigated and implemented for low
volume production.
To be able to verify a device in a short time, special testing
features and design for test (DfT) generally have to be
implemented:
• Insertion of structural testing for digital design (blocks)
such as the exchange of flip-flops with scan flip-flops
• Insertion of special dedicated “test“ registers to guarantee
the control- and observability of analogue blocks
This work has to be done during the design phase and the
fault coverage of these tests has to be checked before the end
of the design phase. Therefore, a test concept for production
testing needs to be done and elaborated before the project
design phase starts.
For manufactured optical semiconductors, the following
procedure is used:
• Manufacture wafers with PCM structures (=dedicated test
structures), verify PCM structures in wafer fabrication site
• Samples are first tested using a (wafer) prober and a
needlecard (probecard) to contact the pads. The failing
samples are marked. This first measurement is done in a
clean atmosphere (open wafers) in the pre-test site, e.g. in
a clean room at CSEM in Zurich. To guarantee correct
operation over the full temperature range, this first test is
done at one temperature within the specified limits (e.g.
hot)
• The good samples are packaged in single-die
packages,on multi-die “chip-carriers” like Multi-Chip-
Packages/Multi-Chip-Modules (MCP/MCM) or bonded
directly on circuit boards (e.g. on “flexprints”)
• The packaged samples are tested a second time at a
different temperature.
An automatic test system for evaluation and small-volume
production testing using a National Instruments LabVIEW® -
based system was chosen as a solution for CSEM. For cost
reasons the measurement hardware is based on PC
components. It consists of a PC with 19 PXI cards (in 2
external racks), a semiautomatic prober in a dark cabinet and
an Ulbricht sphere.
With the above described hardware the main challenge is the
capability to test semiconductors very fast. Therefore,
additional external equipment consisting of a logic analyzer
and a pattern generator were integrated into the system. The
complete testing set-up is controlled from LabVIEW with the
TestStand add-on LabVIEW tool.
The test equipment looks as displayed in Figure 1.
PXI link
Logic
Analyzer
PXI
System
Ulbricht
sphere
RS232
GPIB
PC1: LabVIEW 8.5
XP
DUT
Prober
RS232
PC2: Proberbech
NT4.0
Figure 1: Schematics of the test equipement.
Dark Room
Clean Room
With this setup, small volume production testing can be
performed and an automatic system evaluation flow (system
qualification) can/will be easily implemented. CSEM has now
the possibility to test optical circuits on wafer as well as on
packaged samples.
Due to the high flexibility of this system, circuits with high
frequency requirements and/or with a high pin count can be
tested. Moreover new equipment can be easily integrated in
the future.
This system implementation was possible thanks to the
support of the Wilsdorf foundation which CSEM would like to
acknowledge.
35

Highly Integrated Optical Linear Encoder
C. Gimkiewicz, E. Innerhofer, A. Perkins, C. Lotto, B. Schaffer, S. Schneiter, D. Beyeler, S. Beer, A. Baumgartner, C. Urban,
S. Neukom
Optical linear encoders on moving rail systems have to fulfill stringent size and electrical power requirements with distance resolution capacities in
the 100 nm range. However, cost related issues like packaging tolerances, ruler quality etc. have also to be taken into account.
An optical encoder measures the signal modulation by a light
beam reflected or transmitted by a ruler. By interpolation a
resolution 100 – 1000 times below the grating period of the
ruler is achieved. Ruler inaccuracies like fabrication errors,
degradation effects and dust are partially compensated by
imaging (or shadowing) several tens of grid lines onto the
encoder sensor.
The system development is challenging when a rigorous size
reduction is wanted. In the current system under development,
the image sensor, the light source, the electronic PCB and the
optical module are designed to fit in a total system volume of
50 mm3 . To achieve this compactness the optical paths have
to be folded. Figure 1 shows the layout of the optical system.
Figure 1: Folded telecentric system and illumination system for the
miniature linear encoder.
A light source illuminates the ruler under a certain angle. The
laser written grooves are imaged onto an image sensor with
telecentric lens system to achieve high tolerances versus the
vertical position of the grating in the order of +/- 0.1 mm. The
bright and dark areas detected by the sensor are used to
interpolate the travelled distance. Connecting a set of four
pixels, sine- and a cosine-wave like signals are generated,
yielding the analog quadrature signals shown in Figure 2.
Because of the limited lens size, only a few grid lines can be
imaged onto the sensor. The ruler can be fabricated in steel,
thus stray light has to be taken into account, when designing
the stop. This and the specified system speed of up to 5 m/s
reduce the overall optical power on the sensor for a
measurement cycle. The signal to noise ratio is however
dominated by the shot noise (Figure 3). In the designed first
amplification stage, the noise level is increased only by 3 dB
electronic noise to a total SNR of 47dB.
The resolution of 0.1 µm or 0.5 µm can be programmed. The
signal amplification has to be controlled to optimize the ADC
usage and ensure the accuracy in the complete life-cycle. The
aging of the light source or the degradation of the laser written
grooves due to mechanical abrasion, for example, decrease
the signal amplitude. Therefore, in the digital signal
processing part of the sensor, a calibration routine has been
implemented, which configures the amplification.
36
(a)
Optical frontend
Analog path
A/D converter(s)
Digital processing
Digital quadrature signals
Analog
quadrature
signals
(b)
Figure 2: (a) Principle of the signal generation A0, A1, A2, A3 in the
optical frontend of the image sensor; the yellow squares symbolize
the impinging grating pattern, (b) principle blocks of the sensor.
Figure 3: Spectral noise at the output of the first amplifier stage. The
shot noise level reduces the maximum SNR to 50 dB, the electronic
noise level increases the level over the frequency range by only 3
dB.
Because of cost the total system assembly will result in
alignment errors in the range of +/- 2° concerning the pixel to
grid line orientation. This rotational error changes the slope of
the analogue quadrature signals. For this reason, a
programmable look-up table has been implemented to correct
such signal slope deviations and to make the system a good
candidate for mass production.
This work has been partly financed by the CTI under contract
number 8452.1 NMPP-NM. CSEM thanks them for their
support.

Compact Illumination Modules Based on High-Power VCSEL Arrays
C. Gimkiewicz, M. Columbus, S. Schneiter
Multi-mode VCSEL (vertical-cavity surface-emitting laser) arrays are candidates for compact illumination modules with applications as flash light
illumination for the detailed imaging of fast moving objects (> 100 m/s) or for time-of-flight cameras with modulation frequency in the > 10 MHz
domain. CSEM has realized an illumination unit with modulation frequencies of up to 80 MHz and an optical peak output power of 1.3 Watt.
VCSELs are prominent light sources in the area of in sensing
applications and communication, allowing data rates up to
10 GBit/s. Here, they are proposed for illumination
applications, offering a circular beam profile, low fabrication
cost and long life-time. Especially for the imaging of fast
moving objects they are of interest, since rise and fall times as
short as a few nanoseconds are feasible. The optical output
power per VCSEL diode is in the order of 10 mW; for a
23 VSCEL array it is in the order of 100 mW and for a
complete module it can be in the order of one Watt at a
wavelength of 850 nm. An illumination unit with modulation
frequencies of up to 80 MHz and an optical output peak power
of 1.3 Watt has been realized (Figure 1).
(a) (b)
Figure 1: Photography of (a) a VCSEL array with 23 diodes (Avalon
Photonics), (b) the test board.
One may note that for thermal and eye-safety reasons and for
the shadow free illumination of the field of view it is of
advantage to distribute the laser diode arrays. The developed
test board on a thermally conductive substrate has a size of
45 mm x 45 mm and can support at maximum 16 arrays with
23 devices per array (Figure 1). A high power transistor
driving circuit provides driving currents up to 1 Ampere.
However, in this current range the self-heating of the VCSELs
decreases the optical power. In cw mode for a single array
with 23 devices, this thermal roll-over occurs at around
380 mA at room temperature. In pulsed mode, the self-heating
effect is reduced and peak powers above 130 mW per array
can be achieved (Figure 2).
Figure 2: Optical DC power output of a VCSEL array with 23 diodes
(Avalon Photonics).
In a set-up with 10 VCSEL arrays of this kind, an optical DC
power of 565 mW has been demonstrated. Since the signal
has a sinusoidal shape, the peak power output is 1.33 W at
80 MHz modulation frequency (Figure 3). It has been
achieved with fan cooling, only.
Figure 3: Ten VCSEL arrays are modulated at 80 MHz modulation
frequency. The red line corresponds to the optical power curve, violet
line to the driving current, green line to the voltage and blue line to
the fast Fourier transform signal generated over the sampled interval.
A draw-back of multi-mode VCSELs is their varying far-field
intensity, which is not only dependent on the radiation angle
but also on the driving current: marginal areas of an
illuminated area suffer from a lower, non-linear illumination
intensity at low driving currents, since the higher order modes
appear only at higher driving currents (Figure 4a). With the
help of a diffusing element, the current dependency of the farfield
pattern can be reduced (Figure 4b). The power variation
at a far-field angle of 10° is only +/- 10 % compared to over
+/- 50 % for a laser diode array without diffuser.
(a) (b)
Figure 4: Angular intensity distribution in the far-field of a multi-mode
VCSEL array for different driving currents; (a) with a glass plate in
front of the array only; (b) with a diffusing element at 5.5 mm.
CSEM would like to thank Michael Moser from Avalon
Photonics. This work has been partly financed by the
European Commission under contract number IST-34107.
CSEM thanks them for their support.
37

Generic Framework for Feature Extraction in Vision
T. Zamofing, P. Seitz
A vision system that classifies objects in complex, natural scenes has been realized. This software project tries to map structures of the cerebral
cortex into a hierarchical binary matched filter [1] implemented on a computer.
One of the most ambitious goals in digital image processing is
the development of universal classification algorithms,
capable of “understanding” natural scenes with robustness
and reliability similar to those demonstrated by natural vision
systems, especially by the human visual system. In particular,
the functionality of such natural vision systems under very
adverse conditions is a highly desirable property for practical
applications in machine vision. This robustness can
encompass translation invariance, rotation invariance, as well
as a high tolerance to distortion (e.g. perspective), to partial
occlusion, to reflections and shadows, to unsharp images
(focus, movement). It should moreover be independent of
local contrast and illumination variations, independent of the
background and independent of object texture (surface
texture, dirt, etc.). All classification algorithms are faced, from
the outset, with the problem that the given continuous-tone
images contain a vast amount of information that must be
substantially reduced in order to label the different image
areas (“the objects”) correctly, according to the class to which
they belong.
This feature-matching process is realized as a binary matched
filter following three assumptions (see Figure 1). (1) Local
orientation is a central source of relevant image information.
This assertion is corroborated by neurobiologists’ findings on
how natural vision systems work, using directionally selective
filter banks. The process employs local orientations as the
fundamental picture primitives, rather than the more usual
edge locations. (2) The procedures are based on retaining
and exploiting the local arrangement of features of different
complexity in an image. The technique is based on the
accumulation of evidence in binary channels, followed by a
weighted, non-linear sum of the evidence accumulators. (3)
The algorithm proceeds in a hierarchical fashion, starting at
low feature complexity, and raising the level of abstraction at
each successive processing step.
Figure 1: The feature matching process is based on a successive
hierarchical approach
This algorithm can be implemented very easily in a computer
program. The essence of the algorithm (i.e. without graphics
38
and file handling) can be written using 60–70 lines of a highlevel
language (e.g. Pascal, Fortran or C). Because of the
homogeneity and the simple, reusable characteristics of the
feature-matcher, it should be possible, with reasonable effort,
to develop a hardware implementation running at low power in
real time.
The current implementation uses a black and white firewire
camera with a resolution of 640x480 pixels and is
implemented on a PC using SSE (single instruction multiple
data) for speedup. With this setup a frame rate of 5 to 25
frames per second (depending on the complexity of the
templates) could be achieved. The sample below shows an
example (Figure 2) with its templates to detect traffic signs
that runs at about 20 fps.
Figure 2: Application example: Identification of traffic signs
Future work could use the ViSe (www.csem-devise.com)
sensor. The advantage of the ViSe sensor is that it directly
delivers orientation images with a high dynamic range.
Furthermore a FPGA implementation will lead to a smart, low
power and portable vision system.
[1] G. Lang, P. Seitz, „Robust classification of arbitrary object
classes based on hierarchical spatial feature-matching“, MVA,
1997

Efficient Screening and Formulation Optimization for Polymer LEDs
R. Kern, T. A. Beierlein, T. Offermans, C. J. Winnewisser
A modified pipetting-robot together with an automated opto-electrical characterization system allows speeding up material screening and
formulation optimization [1] of solvent processed organic LEDs. This high-throughput apparatus (HTA-7) allows the fabrication and characterization
of batches of 49 PLED samples in one experimental run. A concentration sweep of individual blend components can quickly reveal the ideal blend
ratio for optimum Polymer LED (PLEDs) composition.
PLEDs may consist of multi-component mixtures of dedicated
materials in order to adjust the desired properties. Most
common goals of formulation optimization include: maximizing
efficiency, minimizing driving voltage, maximizing device
lifetime, and adjusting the emitting color of the PLED. A
promising approach is a host/guest-system, which consists of
the matrix material (host) and an emitter material (guest) in
small concentrations [2, 3] . Further functional materials can be
used to improve the performance. In the following of this
report, a four component system is described: i) host (matrix)
material, ii) guest (emitter) material, iii) hole transporter
(TPD [4] ), and iv) electron transporter (PBD [5] ).
Figure 1 shows efficiency values of devices with a fixed
yellowish/green emitter concentration of 5%. For this material
system PBD concentrations above 20% improve the efficiency
but only if at the same time the TPD concentration is in the
range of 5-10%. The next step is to check whether the chosen
emitter concentration of 5% is optimal.
Efficiency / cd/A @100 cd/m 2
50
40
30
20
10
PBD / %
10
20
40
0
0 2 4 6 8 10 12 14 16 18 20
TPD concentration / wt %
Figure 1: Dependence of PLED efficiency in dependence of holetransporter
(TPD) and electron-transporter (PBD) concentration
In Figure 2a the efficiency is plotted as a function of the
emitter concentration. The TPD and PBD concentrations were
fixed to 5% and 30%, respectively. The emitter concentrations
have been varied up to 10%. A steep increase in device
efficiency is observed below 2% emitter concentration
whereas it starts to saturate at about 10% with values of
~40 cd/A. If the TPD, PBD concentrations will be optimized
again for such emitter concentrations even higher efficiencies
seem to be possible. Figure 2b shows that the emission
spectra exhibit a small shift towards longer wavelengths, when
the emitter concentration changes from 0.5% to 10%.
The high-throughput fabrication tool (HTF-7) uses the robust
spin-coating technique in order to allow forming homogenous
thin films of the various blends with different viscosities.
However, the ultimate goal is the formulation of high
performance electroluminescent inks for applications in the
novel market domain of Printed Electronics.
a)
b)
Efficiency / cd/A @100 cd/m 2
EL intensity / a.u.
50
40
30
20
10
0
0 2 4 6 8 10 12
Emitter concentration / wt %
1.0 Emitter
concentration / %
0.8
0.5
1
0.6
1.5
2
0.4
7.5
10
0.2
0.0
500 550 600 650 700
Wavelength / nm
Figure 2: a) Efficiency as a function of emitter concentration (dotted
line to guide the eye). b) Influence of emitter concentration on
emission spectrum.
Printing will require other additives improving printability. Such
additives in turn need to be characterized in terms of electrical
influence on the device performance, since small changes in
composition of one component might drastically affect the
performance of the complete device. This is an ideal task for
an automated robot system.
CSEM thanks our project partners at Ciba Specialty
Chemicals for their valued cooperation and support.
[1] M. Kiy, et al. “Systematic studies of polymer LEDs based on a
combinatorial approach”, Proc. SPIE vol. 6333, Organic Light
Emitting Materials and Devices X, Z. H. Kafafi, F. So; Eds.
(2006)
[2] G. E. Johnson, et al., "Electro-luminescence from single layer
molecularly doped polymer films", Pure & Appl. Chem., Vol. 67,
175-182 (1995).
[3] X. H. Yang, et al., “Polymer electrophosphorescence devices
with high power conversion efficiencies”, Appl. Phys. Lett. 84, pp.
2476-8 (2004).
[4] TPD = N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine
[5] PBD = 2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole
39

Polymer LEDs Patterned by Ink-Jet Printing
M. Ramuz, T. A. Beierlein, C. Winnewisser
Electroluminescent polymeric LEDs (PLEDs) have been patterned by an ink-jet printing technology. Ink-jet printing process offers significant
advantages for self-emissive pictograms, since it allows adapting with ease the self-emissive area to various layout patterns. A strong market
potential is expected for instance in the domain of custom-designed self-emissive man-machine-interfaces and advertising signage applications at
retailers.
In contrast to inorganic LEDs, organic light-emitting diodes
(OLEDs) are surface emitters that moreover provide wide
viewing angles. These technological advantages amongst
others have allowed OLEDs to enter the market in the form of
flat panel displays for applications in PDAs and mp3-players.
However, other potential applications are attracting industrial
interest as well. Especially in the domain of advertisement,
self-emissive custom-designed OLEDs have become an
attractive alternative. Low-weight OLED pictograms for
example can be produced with thicknesses below 3 mm,
allowing completely new applications like incorporating selfemissive
logos into showcases and windows.
A typical PLED consists of several layers namely the anode,
usually indium tin oxide (ITO), one or two polymer layers and
the cathode, usually a low work function metal. The total multilayer
thickness of such an OLED device is typically less than
one micrometer [1] . In principle, every layer can be patterned.
Several different patterning steps can be applied in the
fabrication process, namely: patterning of the electrodes,
patterning of the electroluminescent material, patterning of the
charge carrier injection layer, and insertion of a patterned
insulating layer.
Usually a photo resist layer on the ITO anode layer is
patterned by photolithography. However, this process is time
consuming and not flexible with respect to the pattern.
Consequently such a process is not favorable for customdesigned
low volume productions.
Figure 1: Cross section of an electroluminescent pictogram based on
organic materials.
In order to manufacture arbitrary shapes, an inverted
insulating thin film is ink-jet printed onto the ITO layer, as
shown in Figures 1 and 2. Charge carriers can be injected
only in the insulator-free areas where light emission will then
take place [2] . Polymethyl methacrylate (PMMA) can for
example be used as printable insulator material.
40
Cathode evaporation (70 nm)
Spin-coat polymer light-emitting
material (70 nm)
Spin-coat PEDOT: PSS (50 nm)
Pattern logo by printing 100 nm thin
PMMA layer as an inverted image
ITO (75 nm)
Glass substrate
As ink-jet printer a dedicated commercial ink-jet printer from
Microdrop has been used. The lateral resolution of the
pictogram is better than 100 µm. This resolution can further
be improved by optimizing the print process parameters, like
nozzle diameter, ink-formulation, ink droplet formation, surface
energies, to resolutions better than 50 µm.
Figure 2: Two examples of ink-jet patterned electroluminescent
pictograms.
Figure 3 shows two different designs of electroluminescent
pictograms. The electroluminescent cross has been
characterized in terms of its electroluminescent performance,
its current voltage characteristic I(V) and its brightness B(V).
The device shows an efficacy of 5 cd/A. The power
consumption per unit area is 19 mW/cm 2 at a brightness of
100 cd/m 2 .
Figure 3: Electrical and optical characterization of a pictogram
This ink-jet printing process will allow low-volume fabrication
of custom tailored signage applications.
[1] Excluding encapsulation layers
[2] M. Kiy, et al., Polytronic 2003 IEEE conference proceedings,
p.111, 21-23 Oct. 2003 ; WO2004068584

Optical Fill Factor Enhancement for Smart Pixels
M. Schnieper, C. Zschokke, F. Kaess and A. Stuck
The fill factor of CMOS vision chips is significantly enhanced using a one-step replication process of micro-lenses with a custom made replication
tool and UV curable ORMOCER ® material.
The use of CMOS technology in imaging devices and vision
chips is today well established. The capability of on-chip
signal processing directly at the pixel site enables the
realization of smart and high-speed vision chips that are very
attractive to many application fields. Such vision chips
however typically show a low fill factor (defined as the ratio of
the optical active area to the full pixel area). It is common to
have only 1/10 of the pixel surface area which captures light,
resulting in a strong reduction of the sensor sensitivity and a
corresponding increase in the required exposure time.
One solution to overcome these losses is to integrate a small
lens on top of each pixel. This lens needs to be designed
carefully in order to match the specific characteristics of the
imaging optic used to collect the light onto the vision chip. A
technology has been developed to deposit in one single step
all the lenses on the chip with a sol-gel replication process.
This requires a chrome master and a special replication mould
master that incorporates the negative shape of the lenses to
be replicated.
Figure 1: Ray tracing for 3 lenses placed respectively in the center of
the chip, between the edge and the center and at the edge of the
chip.
Figure 2: Representation of position correction between microlens
and pixel position.
The most important step in the full process is the fabrication of
the mould master. This requires a suitable micro-lens array
made by SUSS-MicroOptik reflow lenses. The shape and
position are optimized to the specific imaging. The choice of
the latter will also define the maximum possible improvement
of the fill factor. To avoid “vignetting” as shown in Figure 1 a
correction of the micro-lens position with respect to the pixel
center (Figure 2) is included in the fabrication of the mould
master. This re-centers the focal point on the optical active
area of the pixels.
Since each vision chip can have a different layout, it is very
important to ensure correct alignment. This is achieved by the
chrome master. The latter includes alignment marks and also
acts as a frame to UV cure the ORMOCER ® material only
where it is needed. In this way the bonding path and other
required areas are kept free of ORMOCER ® .
Mask
1 st Replication
Figure 3: Representation of the mould master fabrication, with the
replication of the reflow lenses onto the Chrome master.
The fabrication of the replication tool requires a copy of the
reflow lenses onto the chrome master (Figure 3). To ensure a
wafer scale process, all the positions of the lens array moulds
have to be adjusted to the vision chip silicon wafer layout.
After fabrication of the replication tool, a release layer is
applied to it. The release layers developed by CSEM permit
between 50 - 100 replications with the same release layer,
before a new release layer has to be applied to the tool.
Finally, the replication on the silicon chip can be performed.
With one single step a full 5 inch wafer of vision chips can be
processed (an example of replicated microlenses is given in
Figure 4).
Figure 4: Optical and SEM pictures of the manufactured microlenses
By using a very wide angle collecting optic, the fill factor has
been improved by more than a factor 3.
41

MICRO AND NANOTECHNOLOGY
Harry Heinzelmann
Micro- and Nano- technologies (MNT) are key for applications
in many diverse markets. Despite the hype, particularly about
the virtues of “small technology”, innovation only happens if
new technologies bring real advantages over current
solutions. One way to realize the necessary improvements is
by combining R&D efforts in MNT with those in other
disciplines such as mechanics, optics, biology, and classical
materials science. This allows the full potential of “small
technology” to be unlocked, resulting in new products with
new and improved properties.
Micro Electrical Mechanical Systems (MEMS) can be
produced in different materials and countless shapes. The
specific development of MEMS for biological applications
(bioMEMS) and of MEMS with optical properties (optical
MEMS or MOEMS) is of particular interest. The diffractive
grating technology recently developed by CSEM has led to
high performance components that can be integrated in
portable instruments, such as tunable lasers and
spectrometers. Micromechanical cantilever structures find
applications in force microscopy, a technique that is of
increasing relevance in pharmaceutical and medical research.
On the sub-micrometer (or nanometric) scale, plasmonic
effects allow the development of components for improved
light detection and emission. This is extremely interesting in
markets where comparatively small enhancements in
performance represent economically relevant breakthroughs.
Arrangements of microspheres and molecules in regular
nanoscale patterns often give rise to optical effects, which in
some cases can be exploited for optical filtering and switching.
Alternatively, when combined with MEMS technologies, these
arrangements can be transposed into silicon based materials
to produce nanoscale membranes. Under different conditions,
nanoscale objects often arrange into arbitrary arrangements,
with, however, clearly determined statistical characteristics.
These patterns can be exploited for anti-counterfeiting
purposes.
Nanostructured surfaces often show exceptional wetting
properties, giving rise to yet different applications of these
nano-materials. While sol-gel processes allow the surface
properties to be tuned over wide ranges, the electrospinning
of polymers allows the preparation of nanofibrous materials
that could prove relevant for tissue and organ regeneration.
A recent new orientation of biosensing has become possible
following the creation of a start-up company to valorize the
established WIOS technology. The new activities address the
integration of (nano-) sensors in wearable formats such as
textiles. The goal is the realization of monitoring systems for
medical and physiological parameters, e.g. for ambulant
medical applications or integrated in protective wear for high
risk professionals.
43

Dissolved Oxygen Sensor with Self-Cleaning and Self-Calibration
P. Niedermann, J. Gobet • , R. Pfändler •• , P. Bitsche •• , S. Liebert-Winter *, P. Jacob *, T. Overstolz, F. Cardot, A. Hoogerwerf,
A. Dommann
A novel dissolved oxygen sensor for environmental applications has been developed. A gold microelectrode array is used for oxygen measurement
and a diamond auxiliary electrode for self-calibration and self-cleaning, resulting in a low-maintenance, long-lifetime (> 1 year) device. Reliability
and lifetime issues such as dielectric failure modes were addressed using FMEA methodology in order to systematically solve processing issues
and performance limitations.
Figure 1: Sewage treatment
This innovative sensor is used for membrane-less monitoring
of dissolved oxygen in the activated sludge of the secondary
treatment stage in sewage treatment plants [1, 2] , such as the
one depicted in Figure 1.
Figure 2: Measurement principle
The working electrode of the sensor is a gold microelectrode
array, measuring an electrochemical current corresponding to
the reduction of the O2 molecules. The measurement setup is
illustrated in Figure 2. The microelectrodes are insensitive to
fluid flow and permit operation in low-conductivity liquids.
Figure 3: Individual sensing disk surrounded by auxiliary electrode
The sensor chips consist of electroformed gold microdisks
(Figure 3), electrically connected to the highly doped silicon
substrate, and a patterned diamond electrode with a platinum
thin film contact. The diamond acts as a chemically inert
auxiliary electrode, providing self-cleaning by generation of
potent biocide species at anodic potentials (H2O2, O3, Cl2,
OH- ) acting against scale deposition and biofouling, as well as
self-calibration by local dissolved oxygen generation by anodic
polarization.
The fabrication process consists of dielectric layer and
diamond thin film deposition, diamond patterning, diamond
contact metal deposition and patterning, followed by microdisk
44
mold patterning, seed metal deposition and gold electroforming.
Figure 4: Improvement of diamond patterning
The patterning process of the polycrystalline 1 µm thick
diamond layer was improved as illustrated in Figure 4,
allowing seamless integration of this advanced material into
the microsystem. The diamond electrode is contacted by wire
bonding, and the diced chips are packaged in sensor heads
together with a counter and a reference electrode.
Figure 5: Weak spot localization
The evolution from prototypes with promising performance to
a device operating reliably for more than one year was
achieved by failure analysis of field tested sensors and corresponding
corrective actions in the fabrication process and the
measurement protocol, employing failure mode and effect
analysis (FMEA) methodology. Dielectric weak spots were
localized by optical beam induced resistance change
(OBIRCH, see Figure 5) and microdisks were characterized
by focused ion beam imaging.
This sensor is now being introduced to the market.
The wafers were mainly processed at Comlab, the joint IMT-
CSEM cleanroom facility.
This work was partly funded by CTI (project n° 8039.2).
CSEM thanks them for their support.
•
Adamant Technologies SA, La Chaux-de-Fonds
••
Züllig AG, Rheineck
* EMPA, Dübendorf
[1] J. Gobet, P. Rychen, F. Cardot, E. Santoli, “Microelectrode Array
Sensor for Water Quality Monitoring”, Water Sci. Technol. 47
(2003) 127
[2] EP 04 405039.1 “Système d’électrode pour capteur
électrochimique”; EP 05 103304.1 “Procédé d’utilisation d’un
capteur électrochimique et électrodes formant ce capteur”.

Microfabricated Membranes for Cell Layer Culture and Analysis
T. Overstolz, A. Hoogerwerf, M. Liley, F. Spano
A microfabricated membrane chip is being developed for cell culture and analysis. Integrated Pt-electrodes allow the detection of intercellular
junctions and the evaluation of the ‘tightness” of epithelia cell layers. These tools are designed to screen the toxicity of nanoparticles, in particular
their capacity to cross biological barriers such as the lungs.
Nanomaterials based on nanoparticles have become very
popular for many applications, including extremely strong
composite materials based on carbon nanotubes. In parallel
with this development, there has been a growing interest to
study the toxicity of these nanoparticles to the human body. In
vitro methods for these tests are being developed in order to
complement and/or replace large scale animal screening
tests.
In the body, epithelial cells are organized in sheets of cells
that make up the epithelia. All epithelia have the function of
providing a barrier between the body and the external world.
In order to achieve this, individual epithelial cells are joined via
intercellular junctions that make the epithelium impermeable.
Thus, transport across the epithelia occurs essentially through
the epithelial cells (trans-cellular transport) rather than
between the cells (para-cellular transport).
In vitro models of epithelia must be tested for the presence of
intercellular junctions and the absence of gaps between cells,
to ensure that transport across the in vitro model closely
resembles that of the epithelium in vivo. One of the most
widely used approaches to determine the ‘tightness’ of a layer
of cells is to measure its electrical impedance. Electrical
impedances of around 200 Ohm/cm2 may be considered
representative of “good” model epithelia that may be used to
study transport processes.
In order to minimize the influence of artifacts that interfere with
impedance measurements in aqueous media (e.g.
electrolysis, electrochemical potentials, fouling of the
electrode surface), the impedance of cell layers is usually
measured using low frequency alternating currents in a
4-terminal sensing approach. In the 4-terminal sensing
method, one pair of electrodes is used to inject the current into
the system, while a second pair of electrodes measures the
potential across the cell layer.
Figure 1: Silicon chip with integrated platinum electrodes for
impedance measurement of intercellular junctions. The central cell
culture well with its yellow porous Si3N4 membrane is visible. The two
other square holes act as fluidics ports.
Figure 2: Close-up view of Figure 1 showing the square well with the
microporous Si3N4 membrane, inset shows a detailed view of the
hexagonal hole pattern.
To enhance the reproducibility of the measurements the
electrode distance and placement should be well defined.
CSEM has therefore opted to use photolithography to define
the electrodes, rather than the less precise shadow masking
Moreover, the precise electrode definition accommodates
2-terminal impedance measurements, which are still in use.
A microchip has been fabricated integrating a square well for
cell culture including a thin microporous silicon nitride
membrane, on-chip platinum electrodes, and inlets for a
microfluidic system to supply cell culture medium. A
photograph of the resulting chip is shown in Figure 1, whereas
a more detailed photomicrograph of the membrane is depicted
in Figure 2. Thin silicon nitride membranes are especially
suitable for this purpose since they are transparent and thus
compatible with the many optical analysis and detection
techniques used in cell biology.
The fabrication technology starts with the deposition and
structuring of the LPCVD nitride layer that will form the
membrane. The front side structuring defines the hole pattern
in the membrane and the backside defines the opening for the
subsequent etch of the substrate material. Prior to this etch,
when the wafers do not have much topography, platinum
electrodes are deposited and patterned using a photoresist
liftoff. Only after the electrodes are defined the substrate is
etched in KOH to form the membrane.
The next steps foresee the integration of the polymer-based
microfluidic system and the electrical measurements of the
cell layer tightness.
The project partners are the University of Glasgow and the
Katholieke Universiteit Leuven.
This work was partly funded by the European Commission
(Contract number 515843-2). CSEM thanks them for their
support.
45

Metal Micro-Parts Fabrication
F. Cardot
Micro-parts realized by metal electrodeposition onto a silicon mold are presented; the versatility of this process is shown.
Combining silicon deep reactive etching (DRIE) and microelectrochemistry
leads to the realization of high resolution
(~1 µm) and high aspect ratio (up to 30:1) electrodeposited
micro-parts. This process is schematically depicted in
Figure 1. A silicon dioxide etching mask, (a) is realized at the
surface of a highly conductive silicon wafer comprising of a
backside electrical contact (b). The silicon is etched by using a
DRIE process (c) and the silicon mold thus created is filled by
using an electrodeposited metal or alloy (d). The wafer is
polished (e) and the electrodeposited micro-parts are released
(f) by etching the silicon wafer in a KOH solution.
46
a
b
c
Si
SiO2
Ti
Figure 1: Schematic of the fabrication process flow of metal microparts
This process can be used to fabricate a large range of microparts.
For example flexible structures such as springs
(Figure 2) or micro-“FlexTec” structures (Figure 3) have been
realized which could find applications in the field of chip
testing or for the realization of miniaturized mechanical
systems.
a b
Figure 2: Spring micro-parts. a) FeNi electrical contact pin;
b) Ni membrane spring.
Figure 3: Nickel micro-FlexTec hinges
d
e
f
Ni
Non-flexible structures like gears (Figure 4), rack and pinion or
turbines (Figure 5) have been produced, which could be used
in the watch industry.
Figure 4: Nickel micro-gears
Figure 5: Nickel turbine and rack and pinion
This process can also be used for the realization of 3D folded
micro-parts as illustrated in Figure 6. Figure 7 presents an
example of a heterogeneous micro-part made of silicon and
metal. An 8 µm diameter NiFe ball has been electrodeposited
at the top of a silicon needle, 80 µm long and 2 µm across.
Figure 6: Nickel folded micro-box
Si
NiFe
2 ・ m
80 ・
m
Figure 7: Electrodeposited FeNi ball on top of a silicon needle
The work has been carried out within the frame of internal
research for developing new technologies for MEMS
fabrication.

Scintillating Fiber Probes for Neurophysiology
R. Eckert, B. Weber • , A. Buck • , M. Liley, R. Ischer, R. P. Stanley
CSEM has been working with the University Hospital Zurich to develop optical probes for neurophysiology. The results of this development is a
range of probes going from thin probes to be inserted into tissue to large area probes to be used externally for long term measurements.
Radioimaging is widely used as a diagnostic tool in medicine
as it allows the direct imaging of internal structures such as
organs as well as their activity. Of these tools, positron
emission tomography (PET) can give highly accurate images
of the human body. PET has become extremely useful
because compounds used in metabolism can be radiolabelled
so that the signal strength is related to internal metabolic
activity.
Tracing the evolution of these same compounds in time can
also give an insight into the dynamics of metabolism. PET is
too slow for this, a better option is to use a small probe that
can take local measurements in real time. Together with the
University Hospital Zurich and Swisstrace, CSEM has
developed a range of fiber optic based probes for making local
physiological measurements.
All fiber probes have two parts, a short part made from special
fluorescent fibers and a standard glass or plastic optical fiber
to transport the signal to the detection systems. The short
fluorescent fibers convert ・ particles (electrons or positrons)
coming from radioactive decay that penetrate the fiber, into
light. The intensity of the light depends on the energy of the
beta particles. Only a very small quantity of light is produced –
some tens of photons per beta particle.
This light has to be guided without loss to a very low noise
photodetection system. The fibre probes that have been
developed have three different diameters, 250 µm, 500 µm
and 3 mm. The thinnest fibers can be inserted into tissue
without causing damage, while the 3 mm probe has been
designed as a surface probe for chronic (long term)
measurements.
The signal from the thinnest fiber is in the range of 30 counts
per second (CPS) under standard operating conditions.
However, ambient light can also enter the fiber, producing an
unwanted background about ten orders of magnitude larger
than the actual signal. In order to avoid working in complete
darkness, the fibers have to be perfectly sealed against stray
light. Making the fibers light tight is very challenging because
the coating has to be completely opaque to light – even a
single micron-sized pinhole is unacceptable – while being thin
enough to allow the beta particles to reach the scintillating
fiber.
In order to achieve total light tightness, an opaque coating is
applied in a layered fashion and is carefully tested after each
layer to ensure specifications are achieved.
The large 3 mm probes pose additional challenges. Due to
their large area their cross section for ・ rays – which come
from the disintegration of positrons (・ + particles) – is rather
large. As the ・ rays can travel long distances, they are not a
local signal and are therefore an unwanted noise. Optically it
is impossible to tell the difference between fluorescence signal
from the fiber coming from ・‘s or ・’s. Given that the
absorption length for ・ particles is much shorter than that of
・ rays, the ratio between ・‘s and ・’s can be improved by
thinning the fluorescent fiber to a thin disc 3 mm in diameter
but less than 0.2 mm thick. These have been successfully
used to monitor the differences in activity between the left and
right hemispheres of the brain in real time.
A hardware platform was built to read the low light signal from
the scintillating fibers (see Figure 1). This includes ultra-low
noise detectors that are shielded from stray radiation by
integrated shielding. The system is interfaced to a computer
via a USB port.
Finally, the technology developed for the large fiber probes
can also be used to track any radiolabelled material including
nanoparticles. The feasibility of using these kinds of
measurements to check transport of nanoparticles through
biological tissue has been investigated. Initial calculations
show that the systems developed can have already
sensitivities in the 10-13 Molar range which is much better than
competing technologies.
Figure 1: The detection system developed by CSEM including ultralow
noise uncooled photodetectors. The detectors are protected from
background radiation by integrated lead shielding. The system
connects to a computer via a USB port.
This work was funded partly by University Hospital Zurich and
the EU-Project Nanosafe.
•
University Hospital Zurich, PET Centrum, Rigistrasse 56, 8006
Zürich, Switzerland.
47

Towards an Optical Switch with J-aggregates Monolayers
R. Eckert, J. Dintinger • , T. Ebbesen • , R. P. Stanley
J-aggregates are an efficient non-linear optical material. They have been successfully used in ultrafast all optical switches, which exploit plasmonic
effects of nano-structured metal surfaces. This work aims to replace 100 nm thick J-aggregate layers in such switches by a monolayer of
J-aggregates using a unique deposition technique.
Extraordinary optical transmission (EOT) through an array of
subwavelength holes drilled in a metal film relies on the
interplay of surface plasmons (SP) with the periodicity of the
nanostructure to make the otherwise opaque film transparent.
EOT is not only a very active field of basic research but is
currently finding its way into real world applications and
devices.
The concept of an ultrafast all–optical switch, which exploits
EOT, has been demonstrated recently [1] . Its basic component
is a gold film with an array of holes covered with J-aggregates
(Figure 1). J-aggregates (JA) are formed from cyanine
molecules and have well-defined absorption bands. The
difference between their ground and excited states is sufficient
to change the transmission properties of the array.
Consequently, one beam of light (the probe beam) can be
switched on and off by exciting the JA with a second beam of
light (pump beam).
Figure 1: Concept of an all optical switch based on EOT
In the original work the JA were randomly dispersed in a
200 nm thick polymer film coated on one side of the hole
array. The present work aims at achieving the same effect by
using only a monolayer of highly ordered JA formed by a
process developed at CSEM using a template of selfassembled
dendrimers. Both, the remarkable absorption
efficiency of these monolayers and the possibility of coating
both sides of the hole array instead of only one offer the
potential to achieve bigger switching amplitudes between on
and off states of the device.
A typical hexagonal hole array with a JA monolayer on one
side and its transmission spectrum are shown Figure 2. The
holes are milled by focused ion beam (FIB) into a 200 nm
thick gold film deposited on a glass substrate. The array
period is 525 nm and the hole diameter is 175 nm. The
transmission spectrum exhibits two main peaks, which
correspond to the surface plasmon resonances at the
gold/JA/air interface (left) and the glass/gold interface (right).
The dip in the transmission peak at 550 nm is due to the
absorption of the JA monolayer which is less than 10 nm thick.
48
In this experiment, the pump power provided by a cw laser
was not sufficient to excite all JA in the excitation volume and
thereby to induce a sufficiently big change of the index of
refraction necessary to shift the transmission peaks of the
hole array.
Figure 2: a) Electron micrograph of a hole array b) Transmission
spectrum of the hole array
In the next step of experiments, the JA will be pumped by a
pulsed laser, powerful enough to saturate the JA absorption,
which ultimately should cause a shift of the transmission
spectrum to the blue and thus a real switching of the device.
This work was partly funded by the Network of excellence
Plasmon-Nano-Devices within the European Framework 6.
CSEM thanks them for their support.
•
ISIS, Université Louis Pasteur, Strasbourg, France
[1] J. Dintinger, I. Robel, P. V. Kamat, C. Genet, T. W. Ebbesen,
“Terahertz all-optical molecule-plasmon modulation”, Adv. Mat.
18 (2006) 1645

Colour Filters Using Polystyrene Microspheres
M. Guillaumée, M. Liley, R. Pugin, R. P. Stanley
Strong scattering properties are obtained from a single layer of randomly packed polystyrene microspheres, giving rise to structural colours in
transmission. The film colour is dependent on the sphere size, but also on the observation angle. These films might be useful for colour filters with
low reflectivity.
Structural colour is the name given to colours that are
dominated by the structure of the material rather than the
intrinsic properties of the material itself. Such colours are
interesting because they never fade or bleach. An excellent
example is the metallic sheen seen from the wings of certain
butterflies and beetles. The most well-known structural colours
are related to periodic structures (diffraction gratings and
interference films). Random media are also known to be the
origin of several colour effects. This is the case of colloidal
gold and silver nanoparticles, which were already used by
Romans to colour glasses. The blue colour of the sky is due to
the random nature of Rayliegh scattering.
Figure 1: Scanning electron micrograph showing the random packing
of polystyrene spheres
In the present work, strong structural colours are obtained with
a two dimensional random system [1] . The structures are made
with polystyrene microspheres randomly adsorbed onto a
glass substrate (see Figure 1).
Figure 2: Transmission spectra in the visible for dense layers of
sphere diameter Ø
Experimentally various degrees of coverage have been
investigated and the sphere diameter has been varied from
0.2 to 1 µm. When optimized, the spheres in such films
behave as extremely efficient scatterers. Indeed, transmission
can be reduced down to 5% at certain wavelengths (see
Figure 2), producing strong structural colours. The low
transmission range can be shifted by changing the sphere
diameter, thus modifying the observed colour. The colour of
the film colour also depends on the observation angle (see
Figure 3).
Figure 3: Dependency of the observed colour in transmission on the
tilt angle with 725 nm diameter spheres
All these optical effects have been reproduced theoretically. In
the non-tilted case (see Figure 3a), multiple scattering
between spheres is negligible since in this sphere size range
light is mainly scattered in the forward direction. The colour
effect is due to interference between the light incident on the
film and the light scattered by the spheres in the forward
direction.
When the spheres are no longer lying in a plane perpendicular
to the incident light (see Figure 3b), forward scattering from
one sphere even at a small angle can irradiate neighbouring
spheres, modifying the transmitted spectra.
This work was partly funded by the COST project P11,
MieOpic. CSEM thanks them for their support.
[1] M. Guillaumée, M. Liley, R. Pugin, R. P. Stanley, “Scattering of
light by a sub-monolayer of randomly packed dielectric
microspheres giving colour effects in transmission”, Optics
Express 16, (2008), 1440
49

Towards Plasmon Enhanced Detectors
L. A. Dunbar, M. Guillaumée, R. Eckert, E. Franzi, R. P. Stanley
Surface plasmons play a key role in the recent experiments on extra-ordinary optical transmission through nano-structured metals. By tailoring
these nanostructures they can be used to enhance optical transmission, with polarisation and spectral selection. Incorporating these nanostructures
directly onto photon detectors can improve their performance.
To enhance the signal to noise ratio of detectors one can
either enhance the signal or reduce the noise. Recently
Ebbesen et al [1] measured extraordinary optical transmission
through sub-wavelength holes in an otherwise opaque metal.
By exploiting this effect, light can be harvested on
photodetectors and the signal to noise ratio can be increased.
Currently CSEM is fabricating metallic nanostructures on
image sensors to do just this. Additionally these
nanostructured metallic films can act as spectral and
polarization filters or a combination of the two.
Initial trials have been made to investigate the enhanced
transmission through a single slit surrounded by a series of
grooves. Incident light is converted into a surface wave
(plasmon) by the periodic array of grooves. The light is
transported along the surface towards the central slit. This
allows light which does not fall on the central slit, to pass
through the slit and increase the signal that can be detected
with the detector under the slit. As the shot noise depends on
the size detector, increasing the signal whilst maintaining the
same detector size increases the signal to noise ratio. Initial
results give a factor of 5 enhancement per surface area over a
spectral bandwidth of 25 nm.
Figure 1: Scanning electron micrograph showing a slit delimited by 5
groove structures
A typical structure is shown in Figure 1. Here 140 nm of gold
has been deposited onto a CSEM made Vision Sensor. The
metal has a very low surface roughness.
The structures can be optimised for improved signal to noise
ratio, for a specific spectral width or for polarisation sensitivity.
In order to do this the metal thickness, the width and depth of
the groove, the period of the grooves and the initial distance
from the centre of the slit to the first groove need to be
optimised. Slit structures are intrinsically polarisation selective
and by varying these parameters spectral selectivity can also
be modified.
50
Figure 2 shows the transmission through a structured film for
different film thicknesses and shows that the spectral features
can be tuned by varying the metal thickness.
Figure 2: Transmission spectra calculated using 2D-Finite Difference
Time Domain (FDTD) for different metal thicknesses. The peak
transmission shifts to longer wavelengths with increased metal
thickness.
To obtain the desired optical properties is not straight forward
as there is a complex interplay between the various
parameters. Moreover the metal smoothness is crucial both
for losses and to obtain the necessary fabrication tolerances.
The fabrication of tailored nanostructures is currently being
undertaken by focused ion beam which gives both the
flexibility and the precision required.
This work was partly funded by the PLEAS as part of a EU
Project in framework 6.
[1] T. W. Ebbesen, H. J. Lezec, H. Ghaemi, T. Thio, P. A. Wolf,
"Extraordinary optical transmission through sub-wavelength hole
arrays," Nature 391, (1998), 667-669

Unique Marking for Traceability and Anti-Counterfeiting Applications
N. Blondiaux, D. Hasler, E. Franzi, R. Pugin
A technique for the fabrication and identification of unique labels is presented. It is based on the creation of random structures on the surface of the
label and the shape analysis of the structures which acts as a unique fingerprint. The fingerprints produced are then recorded in a database which
is used when a labeled product has to be authenticated.
Counterfeiting of goods is a topical issue for the global market.
For the Swiss industries alone, the losses due to
counterfeiting are estimated at 2 billion CHF per year [1] . Many
markets (tobacco, pharmaceutics, food, luxury goods) are
affected by this rising problem. To fight counterfeiting,
companies must constantly develop more advanced and
tamperproof technologies to make their products difficult to
counterfeit. Another approach is to add identification labels on
the products to ensure their authenticity and traceability
throughout their lifetime.
Figure 1: Workflow for the identification of a labeled item
By combining CSEM competences in nanotechnologies,
microfabrication and imaging / vision sensor technology the
complete chain for the identification of unique objects [2] could
be developed. The fabrication of labels is based exclusively
on self-assembly processes, which are difficult to reproduce
and are extremely low cost.
The technology is based on the fabrication of random
micro- / nano-structured labels as unique fingerprints. After
fabrication, the random structure of the label is characterized
e.g. by means of microscopy and recorded in a database.
When a labeled product is being checked for authenticity, the
random structures of the label are analyzed (shape analysis,
size distribution) and compared with those of the database
(see workflow in Figure 1).
The structured labels are fabricated by means of polymer
demixing. In this process, two immiscible polymers are first
dissolved in a common solvent and the solution is spin coated
on a substrate. During spin coating, the system phase
separates, which leads to the formation of a structured
polymer film at the end of the process. As can be seen in
Figure 2, the final structures have a well defined average size
but are random in terms of shape and distribution. The
average lateral size of the structures can be tuned from
hundreds of nanometers to tens of micrometers by changing
parameters such as the concentration of the solution, the spin
speed or the molecular weight of the polymers
Figure 2: Optical image of a random structure obtained by means of
polymer demixing
The identification system enables checking the authenticity of
the object by using computer assisted microscopy techniques.
The microscope takes several images of the label and selects
the sharpest ones. The image analysis method permits then
the identification of complex shapes in the image and their
distribution for comparison with references stored in the
database.
In Figure 3 such an identification system is presented,
specifically designed to analyze labeled credit cards. Once the
image of the label is acquired on a computer, the structures
are analyzed using custom-made software and compared with
those in the database. The system can then authenticate if the
credit card has been registered in the database.
Figure 3: Schematic of the optical characterization system
specifically designed for the identification of credit cards
The flexibility of the described approach in terms of fabrication
and characterization allows the customization of the complete
chain to the type of object to label. Currently CSEM target
markets include mainly luxury brands.
[1] Institut Fédéral de la Propriété Intellectuelle, Contrefaçon et
piraterie, Etat des lieux en Suisse, (2004)
[2] Patent pending
51

Sol-Gel based Nanoporous Layers as New Sensing Interfaces
E. Scolan, V. Monnier, R. Steiger, R. Pugin
Sol-gel processes are very versatile and well-suited for the deposition of layers with controlled homogeneity, thickness, porosity and associated
surface structures. The high surface area generated by the porosity and the pore size and shape are used to improve the sensitivity and the
selectivity of specifically designed sensors, respectively.
Nanotechnology creates functional materials, devices, and
systems by controlling matter at the atomic and molecular
scales, thus resulting in novel exploitable properties and
phenomena. The control at the nanometer scale is especially
important in the sensor world since most chemical and
biological sensors, as well as many physical sensors, depend
on interactions occurring at these scales.
Sol-gel processes [1] can be broadly defined as the preparation
of designed metal oxide materials at the nanometer scale
(including fibers, powders/particles, shaped/molded bulks,
(thin) films). The gentle wet chemistry route to ceramics has
many advantages. One of the most technologically important
aspects of sol-gel processing is that, prior to gelation, sols are
ideal for preparing thin films, using common coating
processes such as dipping, spinning, spraying or spreading
using a blade, a roll or a bar (see Figure 1). The thickness
(from 10 nm to 100 µm) and adhesion to different kinds of
substrates (glasses, plastics, ceramics, metals, and textiles)
can be controlled over a large range of areas (cm2 to m2 ) with
a high degree of homogeneity.
Figure 1: Bar coater device and plastic sheet bar coated with a
nanoporous sol-gel layer
Figure 2: Specifically designed SiO2 (top) and AlOOH (bottom) based
nanoporous sol-gel layers
52
These processes are a bottom-up approach from molecular
precursors to high purity particulate nano-building blocks
(NBB): their stacking within the film generates tunable porosity
by modifying NBB size, shape, surface chemistry and
interaction with porogenic species. Highly homogeneous
nanoporous layers of silica or aluminum oxide have been
prepared (see Figure 2).
Finally sol-gel processes are an ambient temperature
deposition technology, allowing interfaces with organic and
biological species. Thus film porosity can be functionalized by
grafted or embedded sensitive entities (e.g. dyes, proteins,
polymers or cells), that makes the loaded layers suitable for
high performance chemical sensing applications (see
Figure 3). Nanoporous sol-gel matrices possess chemical
inertness, physical rigidity, negligible swelling in contact with
liquids, high thermal stability and optical transparency.
Moreover the large surface area generated by the
nanoporosity greatly improves the sensitivity of the sensing
films to detect specific diffusing gases or diluted
(bio-)molecules. For instance, optical CO2 gas sensors have
been developed based on the absorbance quenching due to
the interaction of CO2 with encapsulated chromophores [2] .
Figure 3: Concept of nanoporous film based sensor
Due to their tunable size and shape, nanoporous sol-gel
coatings can be integrated into various kinds of devices.
Nanosensors and nano-enabled sensors have applications in
many industries, among them environmental protection,
transportation, communications, building and facilities,
medicine, safety, textiles and packaging.
CSEM thanks the OFES and EC (www.napolyde.org) for their
financial support.
[ 1 ] J. Brinker, G. Scherer, “Sol-Gel Science, The Physics and
Chemistry of Sol-Gel Processing”, Academic Press, San Diego,
(1990)
[2] J.F. Fernández-Sánchez, R. Cannas, S. Spichiger, R. Steiger,
U.E. Spichiger-Keller, “Optical CO2-sensing layers for clinical
application based on pH-sensitive indicators incorporated into
nanoscopic metal-oxide supports”, Sensors and Actuators,
B 128, (2007) 145–153

High Aspect Ratio Nanopores in MEMS Compatible Substrates
A.-M. Popa, R. Pugin, M. Liley
One of the objectives of the European project Biopolysurf is the design and fabrication of smart nanovalves for biology-related applications. The
work presented below concerns the production of nanoporous thin films that will be subsequently functionalized with temperature responsive
macromolecules for the fabrication of smart freestanding nanoporous membranes.
The fabrication of nanoporous membranes is of considerable
interest for many applications including ultrafiltration, osmosis,
prevention of particle emission, high throughput DNA
sequencing and biosensing.
The fabrication of 2D nanopore arrays in ultrathin
(freestanding) membranes can be accomplished by standard
top-down fabrication techniques including Nano Imprint
Lithography, Electron Beam and Focus Ion Beam; however,
these techniques are currently still limited to structuring very
small areas, and therefore, to prototyping. An alternative
approach is the well-known bottom-up approach, where to
scale up the structures one takes advantage of the tendency
of molecular building blocks to self-organize. The bottom-up
methods used for the fabrication of ultrathin films generally
include Langmuir-Blodgett deposition, layer-by-layer
assembly, sol-gel or various biomimetic techniques; however,
only few approaches such as colloidal and block-copolymer
lithography have allowed the fabrication of 2D nanopore
arrays in ultrathin membranes for industrial applications.
Recently, CSEM has developed a silicon based freestanding
nanoporous membrane in which the pore diameter can be
tuned between 10 and 20 nm. The membrane is 60 nm thick
and has been fabricated by combining standard
microfabrication processes and block-copolymer lithography
(a nanostructured block-copolymer thin film is used as etch
mask for the transfer of the self-assembled structure into the
underlying material by deep reactive ion etching). With this
technology, the formation of pores with aspect ratios up to 1:5
could be demonstrated [1] . The nanoporous membranes are
fabricated with a support structure which makes their
manipulation and integration in macroscopic devices
straightforward.
Based on these first results and with the main objective to
improve pore size distribution and the mechanical robustness
of the membrane, a new clean room compatible and wafer
scale applicable etching process has been developed for
thicker silicon based nanomembranes. Once spin-coated, the
block-copolymer thin film is directly used to pattern an
intermediate metal hard mask. This additional step allows to
be reached a much higher selectivity of the etching process
(slower degradation of the mask) resulting in the formation of
pores with aspect ratios higher than 1:10 into a silicon
nanomembrane. The nanoporous thin membranes fabricated
in this way are shown in Figure 1.
According to Scanning Electron Microscopy (SEM) analysis,
the pore channels are parallel throughout the membrane
(lateral undercutting has been avoided using highly
anisotropic DRIE process) and are densely packed in a
hexagonal configuration respecting the initial micelles selfassembled
structures. The pore size distribution is very
narrow and the mean coverage of membrane surface by pore
openings is ~20% of the total area.
Figure 1: Scanning Electron Microscopy (SEM) images (top views
and transverse sections) of silicon nanoporous substrates with 80
and 40 nm diameter pores.
Another big advantage of this approach is the tunability of the
pore size and filling factor (ratio of pores to solid area), which
are both directly linked to the polymeric micellar mask in terms
of diameter and inter-particle distance, respectively [2] . The
next step will be the release of the nanoporous membranes
using standard microfabrication techniques. Subsequently, the
suspended membranes will be modified with temperature
responsive polymers, in order to achieve the foreseen
reversible valve function within the pores. Applications such
as ultrafiltration or biosensing are currently under
investigation.
This work was partly funded by the OFES and the European
Community via the European Research Training Network
project BIOPOLYSURF. CSEM thanks them for their support.
[1] A. Hoogerwerf, et al., “Reinforced Nanoporous Membranes”,
CSEM Scientific and Technical Report 2006, page 41
[2] S. Krishnamoorthy, R. Pugin, H. Heinzelman, J. Brugger,
C. Hinderling, Adv.Funct.Mat., 16, (11), (2006), 1469-1475
53

Nanoporous Membranes for Medical Diagnostics and Drug Discovery
C. Santschi, R. Pugin, V. Spassov, S. Berchtold, A. Hoogerwerf
Understanding cellular signaling controlled by cell surface receptors, ion channels and pumps is a key issue of modern biological research and drug
development. A platform for high throughput measurements, namely, impedance spectroscopy and fluorescence microscopy, has been developed
and is described below. A nanoporous SiO2/SixNy membrane, where native vesicles can be self-assembled, forms the core of the device. These
membranes combined with microfluidic channels are the main components of the modularly built-up unit.
A rapidly growing number of molecular targets discovered by
functional genomics and potential therapeutic compounds
produced by chemical synthesis increases the need to
downscale probe formats in order to accelerate functional
screening, and to reduce reagent consumption [1], and costs.
Recent progress in micro- and nanotechnology allows the
fabrication of suspended nanoporous SiO2/SixNy membranes
appropriate for screening transmembrane receptors and
signaling pathways of mammalian cells. In the frame of this
project financed by CCMX, a versatile platform allowing highthroughput
electrochemical spectroscopy and fluorescence
measurements has been developed. The realization of this
platform is a challenging task merging micro, and
nanotechnology. The modularly built platform consists of three
parts: a micro-fluidic component 1), PCB based Si chip-holder
containing SiO2/SixNy membrane 2), and cover 3) (Figure 1).
3)
2)
1)
Figure 1: Schematic drawing of the modular platform with 1) cover 2)
chip-holder 3) micro-fluidic component.
A system of micro-fluidic channels is sealed between two
glass cover slides. The chip-holder is fabricated using a PCB
board commonly used in industrial electronics. An image of
the chip-holder PCB is displayed in Figure 2. The PCB
contains rectangular apertures, where the individual silicon
chips are placed. Moreover, electric contacts are directly
integrated on both sides of the double layered board. The
cover consists of a glass cover slide and a PDMS sealing
layer.
Figure 2: a) Image of the PCB chip-holder with mounted Si chips.
The size of the board is 4 x 10 cm 2 . b) Closed view showing a blank
cutout where the individual chips can be mounted.
The maximum thickness of the cover is governed by the focal
distance of a fluorescence microscope, which can be as short
54
Glass cover slide
PDMS-Sealing
Chip holder
PDMS-Sealing
Glass cover slide
Fluidic channel
Glass cover slide
Microscope
Fluidic in- and
outlets
Si chip (Figure 3)
PDMS
as 350 μm. The micro-fluidic part of the device is sealed
between two glass cover slides.
SiO2 SiN
Pt
Figure 3: Schematic cross-section a Si chip containing a membrane
The SiO2/SixNy membranes are fabricated from a 4 inch silicon
wafer using standard microfabrication techniques. The wafer
is divided into chips of 5 x 10 mm 2 each containing a
50 x 50 μm 2 freestanding membrane. A schematic crosssection
of the chip is displayed in Figure 3. For size selective
positioning of the vesicles of interest, each membrane
contains nine cavities etched in the SiO2 layer. Furthermore,
each of the cavities contains a single nanopore of 50 nm in
diameter in the center of the underlying SiN membrane as
illustrated in Figure 3. The diameter of the cavities lies in the
range of 1 – 2 μm. For prototyping, cavities and nanopores
have been fabricated using a Focused Ion Beam (FIB)
technique. FIB is a versatile tool which allows surface
structuring by local material removal. The interaction between
a focused Ga + -beam and the substrate results in a physical
removal of material due to a momentum transfer from the
incident ions to the target atoms. Using FIB, structures of
almost any user-defined geometry larger than a few tens of
nanometers can be realized; thus, it is an appropriate tool for
the fabrication of nanopores [2] .
500 nm
Figure 4: Image of the Si-wafer and SEM micrograph of an individual
cavity fabricated using FIB technique
Figure 4 shows an image of a wafer containing several thin
membranes and a SEM micrograph of an individual cavity with
nanopore fabricated with FIB. The next step in this project will
be to perform impedance spectroscopy and fluorescence
microscopy measurements in order to validate the platform
performances for drug discovery applications. This project has
been financed by the Competence Center for Materials
Science and Technology (CCMX) and the CSEM.
[1] S. A. Sundberg, Current Opinion in Biotechnology, 11, (2000)
47-53.
[2] C. Danelon, C. Santschi, J. Brugger, H. Vogel, Langmuir 22,
(2006) 10711-10715.

Stimuli-Responsive Surfaces and Smart Coatings
F. Montagne, R. Pugin
Due to their unique “switchable” properties, stimuli-responsive polymers have been attracting considerable attention in biotechnologies and
successful applications have already been demonstrated in sensing, intelligent textiles and bioseparation. As an illustration of CSEM activities in
the field of “smart” surfaces, presented here are MEMS compatible surfaces modified with poly(N-isopropylacrylamide) (PNIPAM), a thermoresponsive
polymer allowing the control of surface wettability.
Stimuli-responsive polymers, also referred to as “smart”
polymers, are a very interesting class of polymers since they
exhibit marked and rapid conformational changes in response
to external stimuli such as temperature, pH, electric field or
ionic strength. When grafted to surfaces, they confer to
materials unique surface properties as they have the ability to
control hydrophilic/hydrophobic balance, roughness, adhesion
or permeability.
In the frame of HYDROMEL European Project [1] , efforts were
particularly focused on thermally responsive polymers and
developed methods for modification of silicon and gold
surfaces with thin poly (N-isopropylacrylamide) (PNIPAM)
films. In water, free PNIPAM chains exhibit a very sharp
transition temperature, called LCST (Lower Critical Solubility
Temperature), at about 32°C. At temperatures lower than
32°C, PNIPAM chains hydrate to form expanded structures,
whereas they dehydrate and collapse at temperatures above
the LCST. It is a challenge to preserve these remarkable
hydration-dehydration changes when polymer chains are
covalently attached onto a surface in just a few nanometer
thick films. A first grafting method that has been developed
consists in the covalent immobilization of end-functionalized
PNIPAM under melt using reactive silanes as intermediate
coupling agents (ICA) (Figure 1). It is worth mentioning here
that the process can easily be adapted for the grafting of any
kind of functional polymers onto various types of reactive
surfaces (plane or colloidal).
Figure 1: Grafting process for covalent immobilization of tethered
PNIPAM on silicon surface and evidence of surface responsiveness
for a 6 nm thick PNIPAM film.
In the present case, responsive properties could be evidenced
by surface energy measurements showing an increase of the
water contact angle when the temperature is raised above the
LCST (Figure 1). Force measurements performed using
Atomic Force Microscopy in a liquid environment also attested
to a change in the profile of repulsive forces below and above
the theoretical value of LCST.
Thermally responsive micro-patterned surfaces have been
created using micro-contact printing (µCP). This technique,
also referred to as soft lithography, uses a PDMS stamp to
pattern molecules on surfaces. Briefly, the stamp is first 'inked'
with a solution of molecules, dried and then pressed onto the
surface to be patterned. The soft PDMS stamp makes
conformal contact with the surface and molecules are
transferred directly from the stamp to the surface within a few
seconds. As shown in Figure 2, µCP has been successfully
adapted for direct grafting of thiol-terminated PNIPAM chains
onto gold.
Figure 2: SEM picture of thermally responsive PNIPAM microdomains
printed onto gold surface. Size of the domains = 128
microns.
Thermally responsive surfaces are currently evaluated at
CSEM for reversible capture and release of cells. First results
show that cells adhere and proliferate on PNIPAM-modified
surfaces at 37°C (above LCST) and can then be released by
simply decreasing the temperature to 27°C (below LCST).
Based on these results, the year 2008 will see the creation of
patterned thermo-sensitive surfaces with tuned dimensions for
individual cell immobilization, as well as integration of these
components in automated system for cell transfection.
This work was partly funded by the OFES and the European
Community via the European project HYDROMEL. CSEM
thanks them for their support.
[1] HYDROMEL: Hybrid Ultra Precision Manufacturing Process
Based on Positional and Self-Assembly for Complex Micro-
Products – Sixth framework programme priority (NMP)
55

Parallel Nanoscale Dispensing of Liquids for Biological Analysis
A. Meister, J. Przybylska, P. Niedermann, C. Santschi, M. Liley, H. Heinzelmann
Nanoscale dispensing (NADIS) is a technique developed at CSEM to dispense ultrasmall volumes of liquid using specifically fabricated scanning
force microscopy probes. The NADIS probes consist of hollow cantilevers connected to a reservoir located in the chip body. Arrays of NADIS
probes have been developed and produced by micromachining in order to dispense biological liquids in parallel.
The precise handling of liquids with volumes in the femto- and
attoliter range is a challenging task, and one that is becoming
increasingly important for specific applications. For example,
local surface functionalization with biomolecules is used to
create high-density microarrays for diagnostics and biology. In
the future, local application of candidate drugs or
nanoparticles on biological cells may be used to study their
influence on the cell in pharmacology or cytotoxicology.
In CSEM’s nanoscale dispensing, or “NADIS”, the ability to
dispense ultrasmall volumes of liquid at precise positions on a
sample is made possible by combining scanning force
microscopy (SFM) with a custom designed microtool. The
NADIS microtool is similar to a standard SPM probe, except
that the cantilever and the tip are hollow. The microfabrication
process for the NADIS cantilevers is shown in Figure 1.
Figure 1: Fabrication process of the NADIS cantilever probes. a) A
wafer is structured with reservoirs and V-grooves for chip release.
b) A second wafer is processed for microfluidic channels and
pyramidal tips with a silicon nitride layer. c) The pre-structured wafers
are brought together and aligned. d) The wafers are fusion bonded
and a silicon oxide layer is grown by thermal oxidation. e) The hollow
cantilever is released by wet etching. f) The chip is released.
Figure 2: Example of glycerol droplets (left, optical micrograph)
deposited with a tipless NADIS probe (right, SEM micrograph)
The hollow core of the cantilever is instrumental for the
dispensing process as it connects an aperture in the cantilever
tip to a liquid reservoir in the body of the chip. Once the
reservoir is filled with liquid, the hollow cantilever and tip will
be filled by capillarity. Transfer of liquid from the tip aperture to
the surface occurs when the tip is brought into contact with the
sample. First proof of principle experiments demonstrating
NADIS dispensing with glycerol are shown in Figure 2.
56
In order to increase NADIS throughput, systems with multiple
cantilevers were developed. Various designs were defined,
with different cantilever geometries and dimensions. Some of
them are shown in Figure 3 and 4. Different microfluidic
connections between the cantilevers and the reservoirs were
also designed. All cantilevers in an array can be connected to
one reservoir, so that all dispense the same liquid. Or, if
different liquids are to be dispensed, each cantilever can be
connected to its own reservoir. Cantilevers with a double
beam structure are connected to an inlet and an outlet
reservoir, allowing rinsing of the cantilever by flushing a liquid
through it. Tests of these new systems are now underway.
Figure 3: Optical micrograph of two chips with NADIS probe arrays of
different designs (scale bar: 500 µm). The chips are still attached to
the wafer.
Figure 4: Scanning electron microscope (SEM) micrographs of
NADIS probes. a) Array of NADIS probes. b) Detail of an array.
c) Close-up head-on view of a pyramidal shaped tip. d) Detail of a tip
with the aperture at its apex.
The partial support of the Swiss Federal Office for Education
and Science (OFES) in the framework of the EC-funded
Project NaPa (Contract no. NMP4-CT-2003-500120) is
gratefully acknowledged.

Electrospun Scaffolds for Tissue Engineering
F. Spano, M. Liley, C. Hinderling, H. Sigrist •
A novel nanofibrous material is being developed to be used in three dimensional scaffolds for the directed growth of cells, e. g. in nerve
regeneration and guiding. The material will be produced in the form of an aligned mat of nanofibers by electrospinning. The potential of electrospun
polymer nanofiber mats in tissue engineering has been established.
There is strong medical interest in the development of scaffold
materials for tissue regeneration and 2D and 3D cell culture.
In the USA, the shortage of donor organs results in the deaths
of over 6000 people each year. In 1990, there were more than
9000 patients waiting for organ transplants than there were
donors, while today the difference is over 55000 [1] . Tissue
engineering could potentially make a major contribution to
reducing this shortage of donors. Tissue engineering includes
all the techniques that combine cell biology, engineering and
biochemistry to replace, repair or regrow injured or diseased
organs: a way of producing natural or synthetic organs and
tissues by mimicking nature.
Electrospinning is a flexible and effective technique for the
fabrication of polymer nanofibers. In this process, a solution of
polymer(s) is fed at a continuous rate through a capillary. The
capillary is charged to a high voltage (20 kV) with respect to a
grounded counter electrode (Figure 1). This results in very
high electrical fields at the capillary tip leading to the
deformation of the polymer solution into a cone (the “Taylor
cone”) in response to the electrostatic forces. If the electric
field exceeds a certain threshold, the electrostatic forces
overcome the surface tension: a thin jet of liquid is ejected
from the tip of the Taylor cone and travels towards the counter
electrode.
Figure 1: Schematic of the electrospinning process
In tissue engineering, electrospun nanofibrous materials have
been used as three dimensional scaffolds for the directed
growth of cells, e.g. in nerve regeneration and nerve guiding.
The key property that differentiates electrospun materials from
alternative tissue engineering materials is that they mimic the
structure of the extracellular matrix (ECM) (Figure 2). The
native ECM provides more than just a mechanical support for
cells, it also serves as a substrate to display specific ligands
and factors that control cell adhesion, migration and regulate
cell proliferation and function [2] . The addition of ligands to
electrospun materials potentially offers a simple way to control
structural alignment and promote target cell binding.
Different polymers can be used for electrospinning. This study
focuses in particular on Dextran, a polymer known for its
biodegradable and biocompatible properties.
a) b)
20 µm
Figure 2: Phase Contrast Light microscopy (a) and Laser Scanning
Confocal Microscopy (b) images of Neural Stem Cells attached on
aligned PLLA nanofibers [3] .
Simple techniques [4] have been used to control and guide the
nanofibers during electrospinning and create an anisotropic
geometry, e.g. an uniaxially aligned array. Electrospinning
onto shaped electrodes (parallel strips) has been particularly
successful [5] . The diameter of the dextran fibers obtained is
between 100 nm and approximately one micron. The
morphology of the fibers can be tuned systematically by
varying any one of a number of parameters such as
concentration, voltage and distance to the counter electrode.
Defect-free electrospun Dextran nanofibers (Figure 3a) have
been generated in the form of aligned arrays (Figure 3b) and
can thus mimic the structure of the native extracellular matrix
(Figure 3) while exerting an orienting influence.
a) b)
Figure 3: a) SEM image of electrospun nanofibers. b) Optical image
of aligned electrospun nanofibers.
The following months work will focus on the introduction of
biological guidance cues for the controlled growth of cells on
or in aligned electrospun nanofibers.
This work is done within the framework of the CCMX Project
called FUNFIBER with the collaboration of Arrayon
Biotechnology.
•
Arrayon Biotechnology, Neuchatel, Switzerland
[1] American Society of Transplant Surgeons - www.asts.org
[2] F. Yang, et al., Biomaterials, 26, (2005), 2603–2610
[3] F. Yang, et al., Biomaterials, 26 (2005) 2603–2610
[4] X. Mo, et al., Macromol. Symp. (2004), 217, 413-416
[5] Y. Xia, Adv. Mater., 16, No. 4 (2004), 361-366
50 µm
50 µm
57

Detection Methods for Nanotoxicology
S. Angeloni, V. Matera • , E. Verrecchia • , M. Liley
An understanding of the risks due to the short and long term toxicity of engineered nanoparticles requires the collection of a new body of data on
nanoparticle toxicity. In vitro methods can contribute to the understanding of the mechanisms by which NPs enter the human body, but require a
sensitive nanoparticle detection technique. Inductively coupled plasma mass spectroscopy is a promising candidate technique.
An assessment of the hazards due to engineered
nanoparticles (NPs) is highly complex, requiring extensive
data collection on, among other things, the toxicology of NPs.
One approach that can contribute to this assessment is based
on the use of absorption models dealing with oral, inhalation
and topical absorption of NPs (via the intestines, the lungs,
and the skin, respectively) [1] .
Figure 1: An in vitro model of biological barriers for nanotoxicological
tests: a) transport of NPs to the biological barrier; b) microfabricated
well for cell culture; c) cell culture chamber divided in two by a thin
porous membrane (d) layer of epithelial cells acting as model
biological barrier; e) detection of NPs by ICP-MS (see Figure 2).
In vitro assays based on model biological barriers can
contribute to the understanding of the mechanisms by which
NPs gain access to the body (Figure 1). Studies on the
transport (translocation) of NPs across these barriers require
a detection method for NPs with excellent accuracy and
sensitivity. Optical methods such as fluorescence detection or
light scattering can be extremely sensitive. However,
fluorescence labeling has been found to alter the transport
properties of the NPs, while scattering methods have been
found to lack specificity.
Figure 2: Diagram of an inductively coupled plasma mass
spectrometer (ICP-MS, Perkin Elmer): the liquid sample is introduced
(a) into a radiofrequency plasma (b). Ions generated are extracted
from the plasma - (c) and (d) - and separated according to their
mass-to-charge ratio by a mass spectrometer (e); detector (f).
As an alternative to optical detection, inductively coupled
plasma mass spectroscopy (ICP-MS) has been tested for the
detection and quantification of nanoparticles (Figure 2). ICP-
MS is a classical technique based on the chemical
identification of the NPs and profiting from recent
improvements to achieve a better sensitivity (multi-element
ultra trace analysis) [2] . Different water-soluble NPs were
analyzed by this technique, namely, a commercially available
titanium oxide NP suspension (TiO2), cadmium telluride
quantum dots (CdTe), gold colloids (Au, mean size 20 nm),
58
and gold NPs (Au, mean size less than 2 nm [3] ). The NPs
were analysed as pure suspensions, as blends of different
NPs and also in cell culture medium (Figure 3). No
interference was detected between the different NPs or from
the culture medium. A linear response was observed for all
selected NPs allowing not only detection but also facile
quantification. In addition, the sensitivities obtained achieved
the desired detection limits.
Fi
gure 3: ICP-MS response (vertical axis) against known concentration
for gold (top graph) and CdTe NPs (lower graph). A linear response
is obtained despite size differences or the presence of multiple NPs
or cellular culture medium.
In conclusion, the detection and quantification of NPs has
been shown to be possible for inorganic metal NPs down to
concentrations of 0.1 ppb (microgram/liter). Next steps will
involve greatly reducing the sample volume (currently 1 ml) in
order to make ICP-MS based detection compatible with a
miniaturized screening test.
This work was partially financed by the European Commission
in the framework of NANOSAFE2 (NMP2-CT-2005-615843).
CSEM thanks them for their support.
•
Institut de Géologie et Hydrogéologie, University of Neuchatel,
Switzerland
[1] Cell Culture Models of Biological Barriers. Lehr, C.-M. ed.; Taylor
and Francis: London, (2002), 430
[2] D. Beauchemin, Anal.Chem., 78, 12, (2006) 4111-4136
[3] C. Gautier, et al., J.Am.Chem.Soc.,128, 34, (2006) 11079-11087

Using Microtopography to Study Cell Elasticity
M. Giazzon, N. Matthey, G. Weder, M. Tormen, T. Overstolz, M. Liley
Tissue engineering and regenerative medicine are of increasing importance as global life expectancy increases. The development of surfaces to
control cell adhesion and proliferation can make an important contribution to these fields. In this context, microtopographies are used in studies of
the elasticity of human bone cells and as a tool to influence cell growth and survival.
Micro and nano-topography can be used to promote or inhibit
the proliferation of biological cells. One major field of
application of this effect is that of tissue engineering and
regenerative medicine. The control of cell proliferation is of
increasing importance in medical implants with the potential to
accelerate their integration in the body, to reduce the risk of
infection or to avoid undesired cell growth in specific areas.
For this reason a number of research groups are developing
structured surfaces to improve and control the adhesion and
proliferation of living cells [1] .
CSEM has been developing microtopographic structures in
order to study one specific aspect of cell behaviour that
contributes to cell proliferation or death: cell elasticity. This is
the capability of a cell to bend in response to a physical
stimulus. Indeed cells may bend following a stimulus or when
they encounter a mechanical hurdle, but there is a limit above
which they cannot curve [2] .Varying the microtopography
allows that limit to be found.
Microfabricated quartz surfaces with concentric grooves and
ridges constitute a simple system for investigating cell
elasticity. These substrates, obtained by photolithography,
have ridges and grooves with a width of 2 or 4 µm and a
range of depths from 30 nm to 500 nm. The radius of
curvature of the ridges varies across the quartz substrate
testing cell elasticity under a range of conditions in one
sample.
When bone cells are grown on these surfaces they are found
to assume different morphologies. Where the radius of
curvature is high the cells adopt an elongated morphology
(Figure 1b), following the ridge and groove structure. In
contrast, where the radius of curvature is small the cells
spread over the grooves and ridges (Figure 1a).
Figure 1: Bone cells on concentric grooves with a high curvature (a)
and with a low curvature (b). Cells spread and orient normally on the
flat surface in the top left of b. In the bottom right the cells are
elongated and align to the grooves and ridges.
The cytoskeletal protein, actin, forms fibres that play a crucial
role in cell spreading, movement and adhesion [3] .
Immunofluorescence staining of actin fibres allows the study
of the form and structure of adherent cells on quartz surfaces
(Figure 2). The response of the cells seems to be linked to the
rigidity of the actin fibres. Shallow grooves with a low
curvature result in a partial alignment of the cells, which cross
a few grooves only: the actin fibres are well aligned to the
grooves: close to the centre of the structure the cell is unable
to align to grooves with a high curvature: the actin fibers and
the cell span the ridges with no alignment. However, when the
depth of the grooves is 500 nm or more, a large number of
cells undergo apoptosis, or programmed cell death.
Figure 2: Fluorescence images of actin fibers (green) of bone cells
grown on concentric lines (a) close to and (b) far from the centre of
the grooves. (c) cell nuclei aligned to the circular grooves and
(d) triple fluorescence staining of cells far from the centre with actin in
green, the nuclei in blue and focal points in red.
In conclusion, groove microtopographies influence cell
behavior in vitro. Future work will focus on deep
microtopographies – deeper than 500 nm – and their influence
on cell apoptosis. This may form the basis of a new strategy
for the control of cell proliferation and death.
This work was partly funded by the European Commission in
the context of the Marie Curie research training network
BioPolySurf (www.biopolysurf.net). CSEM thanks them for
their support.
[1] F. Rehfeldt, A. Engler, A. Eckhardt, F. Ahmed, D. Discher,
”Cell responses to the mechanochemical microenvironment-
Implications for regenerative medicine and drug delivery”,
Adv Drug Deliv Rev., 59, (2007)1329
[2] P. Kunzler, C. Huwiler, T. Drobek, J. Vörös, N. Spencer,
“Systematic study of osteoblast response to nanotopography by
means of nanoparticle-density gradients”, Biomaterials, 28,
(2007) 5000
[3] C. Wilkinson, M. Riehle, M. Wood, J. Gallagher, A. Curtis,
“The use of materials patterned on nano-and micro-metric scale
in cellular engineering”, Materials Science and Engineering, 19,
(2002) 263
59

Composite Materials for Bone Implants
M. Giazzon, M. Liley, G. Weder
CSEM is developing methods to nanostructure (‘texture’) composite materials for use in orthopaedic implants. Photolithography and bead
lithography methods are used to create master templates that are then replicated in a resin matrix. The structures will be tested for their effect on
bone cells in vitro.
The use of orthopaedic surgery to replace joints and repair
bone defects is increasing rapidly. Due to a more active aging
population, the demands made on the materials used in these
operations are also increasing: improved robustness, longer
lifetimes and easier surgical procedures are expected for hip
implants and other joint replacements.
Metals have been used with enormous success in orthopaedic
surgery, but there are still some problems associated with
their use. While issues such as weight and thermal
conductivity can be important for specific applications such as
cranial repair, one major issue of almost universal importance
is that of Young’s modulus. The high stiffness of metallic
implants results in a mismatch in its mechanical properties
and surrounding bone. This in turn leads to “stress shielding”:
loss of bone mass and weakening of the surrounding bone
that may lead to implant failure. In this context, the repair of
osteoporotic bone remains a major challenge.
As a partner in the EU project Newbone, CSEM is working to
develop composite materials that can be used in orthopaedic
surgery. Glass-fibre reinforced composites (FRCs) based on
polymeric materials currently used in dentistry are being
tested and optimised for applications in bone repair. CSEM’s
contribution is to test the effect of surface coatings and
modification, with the goal of developing surface micro- and
nanostructures that enhance cell growth, cell adhesion and
the integration of the implant into the surrounding bone.
Figure 1: Hemispherical pits fabricated by replication in a bis-
GMA/TEGDMA resin matrix
The micro- and nanostructures are fabricated in the surface of
the resin composite matrix by replication. The original
(“master”) structures are made by photolithography, in the
case of microstructures (Figure 1), and bead lithography for
the nanostructures (Figure 2). In a first stage, the two types of
structures will be tested separately for their effect on cultured
bone cell lines. Previous studies on dental implants have
shown that multi-length scale topographies give the best bone
60
integration. So, combinations of the individual structures that
give the best results will also be tested.
Figure 2: Pillar structures in a silicon master
CSEM is also developing methods to determine the reaction
of bone cells to structured surfaces. In addition to previously
reported new methods to directly measure cell adhesion are
being investigated. One of the most promising of these
methods uses a specially adapted atomic force microscope
(AFM) to measure the force necessary to pull individual cells
from the surface (see Figure 3).
Figure 3: Direct measurement of cell adhesion: a) A cell attached to
an AFM cantilever is brought towards the surface. b) The cell
contacts the surface. c) The cell is pulled away from the surface. The
deflection of the cantilever is measured to determine the force
applied to the cell. d) The cell is released from the surface.
Initial results with this technique are promising, and it is hoped
that it will give new insights into the influence of surface
modification on the interactions between bone cells and
surfaces.
This work was partially financed by the European Commission
in the context of the Project Newbone (NMP3-CT-2007-
026279). CSEM thanks them for their support.

Simultaneous Detection of Four Antibiotic Families in Milk for Customer Safety
G. Voirin, R. Ischer, S. Pasche
A biosensor for the detection of four antibiotic families has been realized and tested with reference milk samples in collaboration with European
partners. The simultaneous detection and identification of antibiotics in contaminated milk has been demonstrated.
In the dairy industry, it is important to avoid contamination of
milk with antibiotics which could modify the fermentation
process of dairy products such as cheese or yogurt, or
possibly cause allergic reactions in consumers (Figure 1). In
the frame of the European project GoodFood [1] , a biosensor
system for the detection of several antibiotics has been
developed in collaboration with other European partners.
CSEM has focused on a biosensor detection system based on
the interrogation of the resonance wavelength of a waveguide
grating coupler (WIOS Wavelength Interrogated Optical
Sensing). The relevant antibiotics were identified during a
survey made in 30 countries around the world. Four antibiotic
families were selected: sulphonamides, fluoroquinolones,
beta-lactams and tetracyclines.
Figure 1: Milk chain from production to consumer, screening test
must be performed as early as possible
The detection system is based on the change of the refractive
index of the sensing surface due to the binding of molecules.
The refractive index change induces a shift in the resonance
wavelength of the waveguide grating coupler which is
interrogated using a periodically swept tunable laser. This
detection method is sensitive to refractive index changes on
the order of 10-6 , or the equivalent of several pg/mm2 of
molecules binding to the sensor surface.
A competitive immunoassay format was chosen for the
detection of the antibiotics. A specific sensing surface was
obtained by using recognition molecules such as antibodies
and receptors, developed by GoodFood partners. Specific
antibodies for the sulphonamide and fluoroquinolone antibiotic
families were obtained by immunization of rabbits, and are
specific for a whole family of antibiotics (a family is a group of
molecules with similar chemical structures). Receptor
molecules specific for the beta-lactams and tetracycline
antibiotic families were specially engineered to present a high
affinity for a group of molecules. For each family, a test
protocol was implemented on the biosensor platform and the
cross reactions with the other reagents and antibiotics were
tested. The goal was to obtain a biosensor platform with
different sensing regions each specific to one antibiotic family,
allowing detection in the different regions simultaneously with
a unique milk sample. Using optical detection allows
measurements on eight separate pads simultaneously.
Figure 2 presents the calibration curves for each antibiotic
resulting from competitive immunoassays.
Figure 2: Calibration curves for sulphonamides, fluoroquinolones,
beta-lactams and tetracyclines
Validation of the detection system was performed in the
laboratory of the Nestlé Research Center in Lausanne in the
frame of a workshop where different methods developed in
GoodFood were compared. Reference milk samples with
known concentration of antibiotics were used for these tests.
The response signal observed with the milk sample on the
different reactive regions of the chip were compared to the
value obtained with milk contaminated at the maximum
residue limit level (MRL). Figure 3 displays the results
obtained for the different reference milks, demonstrating that
the four antibiotics can be detected at the MRL level.
Figure 3: Measurement of different milk samples for the simultaneous
detection of four antibiotics (dotted lines indicates signal at the MRL)
In the frame of the GoodFood project, it was possible to
develop a biosensor platform for the detection of four
antibiotics families simultaneously at the maximum residue
limit set in the legislation. Adapting this technology for Lab-
On-a-Chip [2] will provide a tool for antibiotic screening at the
farm level or before entering the dairy factory.
This work was funded by SER, European Project FP6-IST-1-
508774-IP and OFFT. CSEM thanks them for their support.
[1] www.goodfood-project.org
[2] G. Suárez, et al., “ Food Safety with the Help of a Miniaturized
Laboratory”, in this report, page 64
61

Smart Wound Dressing with Integrated Biosensors
S. Pasche, R. Ischer, S. Angeloni, M. Liley, J. Luprano, G. Voirin
Specific biosensors are being developed for the in situ monitoring of wound healing, focusing on pH measurements and on the detection of
infection markers. Ambulatory, real-time monitoring will be made possible by integration of these sensors in wound dressings.
Online health monitoring often requires hospitalization, which
can become an expensive and inconvenient choice for the
patient. In this perspective, wearable sensors that allow in situ
biosensing without hospital surveillance constitute a very
promising technology. The European project BIOTEX (“biosensing
textile for health management”) [1] aims to integrate
sensors in textiles for medical applications. The CSEM goal is
to develop immunosensors for a continuous control of the
wound healing process, which are based on pH changes, as
well as on the concentration of an inflammatory protein, the
C-reactive protein (CRP).
Sensing principles include the use of responsive hydrogels
that swell in response to changes in the environment
(Figure 1a), and the use of functional surfaces that specifically
recognize the target protein (Figure 1b). Swelling of
pH-responsive hydrogels is a consequence of charging of the
polymer chains that form the hydrogel. Functional surfaces
rely on a dextran polymer layer (OptoDex ® ), which prevents
non-specific adsorption from the biological medium and at the
same time acts as covalent glue for immobilization of the
receptor molecules.
Figure 1: Sensing principle for (a) a responsive hydrogel, and (b) a
protein-selective surface
Detection is based on an optical signal, using the evanescent
field of light propagating along a waveguide, to probe
refractive index changes. Both hydrogel swelling and
biomolecule adsorption induce changes in the refractive index
above the surface, which affect the propagation of the
waveguide mode. An optical sensing system consisting of a
white light source (LED) and a detection spectrometer, which
can be easily integrated into a wound dressing patch, has
been designed (Figure 2).
Figure 2: Optical detection scheme, comprising illumination with
white light, light propagation along the waveguide, and wavelength
detection with a spectrometer.
This system allows in situ optical detection of volume changes
of a hydrogel layer deposited on a waveguide substrate, with
sensitivity better than 10 -4 refractive index units,
corresponding to polymer swelling on the order of 1% and to
an adsorbed mass of ~100 pg/mm 2 .
62
Reversible optical monitoring of hydrogel swelling with
response to pH was demonstrated using a pH-responsive
hydrogel (Figure 3a). The range of pH sensitivity can be tuned
by changing the hydrogel chemistry. Monitoring of the
concentration of CRP was performed using a specific surface
chemistry with CRP receptors immobilized on dextran-coated
waveguide chips (Figure 3b).
a)
b)
Figure 3: In situ optical monitoring of (a) pH, using a pH-responsive
hydrogel, and (b) changes in the concentration of CRP in serum,
using a functional surface with immobilized CRP receptors.
In situ measurements are possible after integration of the
biosensor into a wearable sensing patch (< 0.2 cm 2 ) that is
connected via optical fibers to the detection system and power
supply (Figure 4).
Figure 4: Sensing patch design to be later integrated in the wound
dressing
The sensing patch will later be integrated into wound
dressings or bandages, which will provide online information
on the state of the wound healing process. This novel
technology will be particularly valuable in applications such as
the ambulatory supervision of skin grafts and ulcer treatments.
This work is partly funded by the European Commission,
FP6-IST-NMP-2-016789 and FP6-IST-026987. CSEM thanks
them for their support.
[1] www.biotex.eu.com

Biosensors for Drug Prevention
B. Wenger, A.-M. Popa, S. Pasche, R. Pugin, G. Voirin
The biosensing platform developed at CSEM is an attractive solution to detect illegal drugs and other substances concerning the security of
citizens. However, to match the detection limits set by official authorities, the sensitivity must be improved. Therefore, an approach based on the
nanostructuration of the sensing surfaces to increase the amount of analyte that can be trapped at the interface has been tested.
A major issue in the security of public buildings and transport
is the fast and specific identification of substances such as
chemical and biological toxic agents, explosives and illegal
drugs. Continuous monitoring of trace concentrations in
conjunction with detoxification systems is envisioned to
protect people from terrorist threats. The wavelengthinterrogated
optical sensing (WIOS) system developed at
CSEM offers the versatility to tackle several of these target
analytes.
The detection mechanism of this instrument is based on the
measurement of a change of refractive index at the surface of
a waveguide. Monochromatic light is coupled into and out of
the waveguide through gratings and the laser is tuned in order
to find the resonance wavelength corresponding to the given
coupling angles and the effective index of the waveguide. The
chips are usually functionalized with a specific biological
receptor (e.g. antibodies) and adsorption kinetics are
monitored in real time through a change in resonance
wavelength.
In this project, the functionalization of the surfaces was a
result of the collaboration with external partners. Securetec
Detektions-Systeme AG provided cocaine-binding antibodies
and a hapten conjugate featuring several attached cocaine
molecules. One of these substances is attached to the surface
of the waveguide by means of a photo-crosslinkable polymer
(OptoDex®, Arrayon Biotechnologies) while the second is
used in solution together with cocaine for competitive
immunoassays (Figure 1).
Figure 1: Competitive immunoassay for cocaine detection
The detection limit for cocaine for this assay is around
100 ppb. A typical application of this technique would be to
find traces of illegal drugs in shipping containers. However,
because of the very low volatility of this compound only traces
are present in air. Therefore, lower detection limits are
required. Although pre-concentration is feasible during the
sampling step, improvement of the current platform is more
desirable.
One way to enhance the signal is to make the surface rougher
in order to increase the amount of analyte that can be probed
in the evanescent field of the guided light mode. As the
penetration depth of the wave into the solution is less than
200 nm, nanostructures are required.
As a first trial, mesoporous layers made of metal oxide
nanoparticles (SiO2, AlOOH,...) were deposited and stabilized
with a polymer. After functionalization, these layers showed
enhanced detection sensitivities up to 3-5 times for model
proteins. However, due to the size of the pores, the
penetration of the proteins into the mesoporous network was
slow and incomplete.
The second approach was to form nano-pillars and nanoholes
in a thin silica layer deposited on top of the waveguide.
An in-house procedure [1] based on block copolymer inverse
micelles as templates was used (Figure 2). The depth of the
features is typically up to 100 nm making the entire
nanostructure accessible to the evanescent field of the guided
light. Thus, the transducer surface area is drastically
increased.
Figure 2: Nano-pillars (right) and nano-holes (left) in SiO2 realised by
etching on WIOS grating chips. Depth: ~80 nm, distance between
pillars: ~200 nm.
These roughened surfaces are currently under investigation.
They will be optimized for the WIOS measurement system
and the signal enhancement will be characterized
This work was funded by the European Community via the
Integrated Project NANOSECURE NMP3-CT-2007-026549.
[1] S. Krishnamoorthy, et al., Langmuir, 22, (2006) 3450-3452
63

Food Safety with the Help of a Miniaturized Laboratory
G. Suárez, S. Pasche, R. Ischer, G. Voirin, N. Schmid, J. Auerswald
A miniaturized laboratory, often referred to as a “lab-on-a-chip”, based on the Wavelength Interrogated Optical Sensing (WIOS) system has been
developed for the simultaneous detection of several residual antibiotics in fresh milk.
One of the major challenges in food safety is integrating
quality control into the process of production and/or
commercialization. Specifically, the analysis must be accurate,
fast, cost-efficient, disposable and easy to operate by the nonskilled
technician. In the milk industry in particular, levels of
residues of veterinary medicinal products, of which antibiotics
represent a significant part, are strictly regulated by the
European Union legislation. More precisely, a series of four
families of antibiotics are found to be of particular interest:
・・lactams, tetracyclines, sulfonamides and
fluoroquinolones. In the framework of this CCMX
(Competence Centre for Materials Science and Technology)
project, the side-by-side development of a label-free multidetection
system and an integrated microfluidic cartridge
converges to simultaneous and fast detection (< 15 min) of
four antibiotics in the field environment.
The label-free multidetection system is based on WIOS
technology developed at CSEM and allows sensitive detection
of biomolecules adsorbed on the waveguide chip. The
selective adsorption of molecules from the solution induces a
change of refractive index at the interface which is monitored.
Competitive immunoassays based on the specificity of either
antibodies or receptors have previously been developed for
the simultaneous multi-detection of antibiotics and have been
optimized in the framework of the European project
GoodFood [1] . The other aspect of this work consists of
developing and fabricating a microfluidic cartridge that
integrates both the sensor chip and the reagents required for
the assay. Currently the cartridge is fabricated from a piece of
plastic (PMMA) of dimensions 10 x 4 x 0.7 cm in which
channels and reservoirs are machined by micromilling.
Prior to the analysis, a small volume of milk (≈ 1 ml) is
introduced into a vial containing the assay reagents. The vial
is closed with a rubber-cap and introduced upside down into
the sample vial holder located on the microfluidic cartridge.
Two needle-inlets on the base of the vial holder pierce the
rubber-cap and connect the sample to the fluidic system.
Figure 1: Setup of the analysis system
In terms of fluidics, the overall setup of Figure 1 is based on
the use of a single syringe pump working in aspiration mode
coupled with a multiposition valve connected to atmospheric
64
pressure. The basic idea behind the setup is to control which
liquid (sample, buffers…) is driven through the cartridge
channels by submitting its reservoir to the atmosphere while a
negative pressure is applied at the other end of the cartridge.
Moreover, the use of a 3-port valve on the pump allows for
two possible pathways on the cartridge: the loading path (to
deviate residual air from the sensing chip) and the sensing
path which addresses the liquid to the sensing regions for
reaction/measurement. Waste reservoirs ensure that no
residual liquid goes out of the cartridge. With this simple setup
neither the valve nor the pump are directly in contact with the
solutions used during the assay; thus, no contamination
occurs.
Figure 2: Picture of the whole detection setup with microfluidic
cartridge inserted into holder interface (grey box)
The system (Figure 2) was tested successfully with spiked
milk samples demonstrating the automated detection of two
antibiotic families (sulfonamides and fluoroquinolones)
(Figure 3).
Figure 3: Typical signals obtained for antibiotics detection in milk
This system that is currently under optimization for antibiotics
detection in milk remains easily adaptable to further
applications (eg. food analysis or biomedical diagnosis).
This work was funded by CCMX-MMNS Lab-On-a-Chip
project, European Project FP6-IST-1-508774-IP and OFFT.
CSEM thanks them for their support.
[1] G. Voirin, et al., “Simultaneous Detection of Four Antibiotic
Families in Milk for Customer Safety”, in this report, page 61
www.goodfood-project.org

Wearable Biosensors in Protective Clothing
G. Voirin, S. Pasche, R. Ischer, E. Scolan, M. Tormen, G. Dudnik, J. Luprano
A non-invasive biosensor for the detection of stress markers, such as lactate in sweat, is being developed. This system will be directly integrated in
the garment of professional rescuers and fire-fighters to improve the safety of these professionals during their intervention.
In the European project BIOTEX [1] , CSEM developed a
miniaturized label-free biosensor system for application in
wound dressing [2] . The European project PROETEX [3] aims at
developing textile and fibre based, integrated, smart wearable
sensors for emergency disaster intervention personnel with
the goal of improving their safety, coordination and efficiency.
A non-invasive, wearable biosensor is currently being
developed for the detection of biological parameters in sweat.
An examination into the needs of workers from the field of
disaster management (town and forest fire-fighters, civil
protection, etc.) has indicated the importance of controlling
one’s physiological stress during intervention under
dangerous conditions such as heat, low visibility and a low
oxygen. As the blood lactate level is a known indicator of
physiological stress, the aim of this project is to develop a
non-invasive biosensor that directly measures lactate levels in
sweat.
An initial biological detection system is based on responsive
hydrogels that shrink or swell in response to an external
stimulus (lactate concentration). The polymer chains of the
hydrogel are functionalized with specific enzymes (lactate
oxidase) that are incorporated before polymerisation.
Conversion of lactate to pyruvate changes the ionic
concentration in the hydrogel, which affects the hydrogel
volume by an osmotic effect (Figure 1).
Figure 1: Swelling of an enzyme-responsive hydrogel due to an
osmotic effect
The volume change of the hydrogel directly translates into a
change in refractive index that can be monitored with a label
free optical biosensor based on the wavelength interrogation
of a waveguide grating coupler. A miniaturized system
comprising optical fibres, a lens and a waveguide grating will
be integrated into a textile garment (Figure 2). A micro
spectrometer based on a MEMS tunable grating [4] is presently
being developed for detection of the wavelength shift;
however, for initial tests, a commercial mini spectrometer has
been used.
Figure 2: Sensing principle and realized scheme using waveguide
grating, lens and optical fiber
In a second approach, the sensing layer is placed directly on
optical fibres that can easily be integrated in a textile structure.
In this case, a colorimetric approach was chosen using pH
indicators incorporated in a sol-gel matrix that is deposited on
the core of the optical fibre. Sensitivity to lactate is obtained by
incorporating a specific enzyme in the sol-gel matrix.
Preliminary results on the fabrication of pH sensitive sol-gel
are shown in Figure 3.
Figure 3: Color change of a pH sensitive sol-gel matrix exposed to
different pH
The use of miniaturized biosensors allows their integration in
textile garments for the non-invasive monitoring of a biological
marker of stress directly in sweat. This next generation of
smart garments will improve the safety of professional
rescuers during dangerous intervention.
This work is partly funded by the European Commission:
project FP6-IST-026987. CSEM thanks them for their support.
[1] www.biotex-eu.com
[2] S. Pasche, “Smart Wound Dressing with Integrated Biosensors”,
in this report, page 62
[3] www.proetex.org
[4] M. Tormen, “TUGON – Compact MEMS-based Spectrometers
for Infra-Red Spectroscopy”, in this report, page 19
65

NANOMEDICINE
Peter Seitz
Mandated by the authorities of the Canton of the Grisons and
the Principality of Liechtenstein, CSEM has carried out an indepth
study of the feasibility of a new innovation center in the
Alpine Rhine Valley, with the main objective of significant
economic impact in this region. To this end, the new CSEM
innovation center must build up activities and competencies in
a domain where an already well-established regional industry
cluster can be found, but for which CSEM has a lot of preexisting
technologies and know-how to offer.
In close collaboration with the regional industry, research
organizations, universities and the political authorities, the
novel and highly promising area of Nanomedicine has been
selected. Since the Alpine Rhine Valley is already home to a
substantial, successful MedTech cluster and CSEM has a rich
portfolio of nanotechnological solutions to offer, Nanomedicine
appears to be a natural choice.
According to the European Science Foundation,
Nanomedicine is defined as the science and technology for:
• Diagnosing, treating and preventing diseases and
traumatic injury
• Relieving chronic and acute pain
• Improving and prolonging human health,
through the use of molecular instruments and tools, and by
understanding the functioning of the human body on the
molecular level [1] . In short, Nanomedicine is “Nano for Health”.
The driving force for the activities of CSEM is rarely scientific
curiosity but most often the creation of huge economic impact
through the development of products and services with
significant value for large user communities. For this reason, a
key question to be answered is whether Nanomedicine has
the potential of making significant contributions to the future of
health care. Due to the current vast demographic change
(over-ageing population), large world-wide industrialization
and growing expectations for a better quality of life in our
society, health care costs are exploding. To moderate this
development, the future of health care is envisaged to be
heading in the direction of 4P medicine, which will be:
• Personalized, through the use of cost-effective, individual
diagnosis, therapy and monitoring
• Predictive, by establishing and exploiting personal
genome and health risk profiles
• Preventative, thanks to cost-effective screening,
therapeutic and long-term observation methods (find-fightfollow)
• Participatory, by empowering the patient and her caregiver
in clinical environments and at home.
On-going research in Nanomedicine is targeting key elements
of 4P medicine – from low-cost gene profiling, over novel
functional imaging methods for living cells, to miniaturized
theranostic systems (integrated combinations of diagnostic
and therapeutic devices) – to contribute substantially to
turning this vision into reality.
Building on traditional strengths of CSEM, the particular
contributions of the new CSEM Research Center for
Nanomedicine in Landquart are foreseen in the following four
areas:
• Functional nano-imaging, by exploiting element-sensitive
X-ray techniques and advanced fluorescence microscopy
methods for the acquisition of 2D and 3D images of living
cells in real time and with sub-micrometer resolution. This
will provide new insight into the functioning of cells under
various conditions.
• Bio-selective surfaces, through the functionalization of
metallic, dielectric, plastic and ceramic surfaces with
organic or inorganic layers with application-specific
properties, such as anti-bio-fouling or enhanced bone ingrowth.
• Versatile cell growth reactors, as major tools for
toxicological tests of novel substances (“cytotox platform”)
enabling significant reduction of animal testing, as well as
for regenerative medicine, allowing the production of large
quantities of differentiated cells from a small quantity of
patient-supplied healthy cells.
• Robust medical sensing, with the aim of providing novel
sensing principles and devices, capable of yielding reliable
measurement results of critical vital parameters over long
periods. This includes “smart tubes” for the sensitive and
selective gas analysis in human breath, as well as EIT
(electro-impedance-tomography) systems on various
scales.
The activities of the fledgling CSEM Research Center for
Nanomedicine have already resulted in the creation of a first
startup company, Dynetix AG, providing label-free bio-sensing
solutions [2] . This has only been made possible through the
support of other CSEM divisions, which provided key
elements of the technology at Dynetix.
True to its main mission, the CSEM Research Center for
Nanomedicine has already started several applied research
projects in the four domains summarized above with high
potential for lasting economic impact in the Alpine Rhine
Valley, through close collaborations with regional industrial
partners, by providing SME with technological solutions and
access to the vast R&D network at CSEM, as well as with the
preparation of more startups to be created in the coming
years.
[1] European Science Foundation, “Nanomedicine – An EMRC
Forward Look Report“, ESF 2005
[2] Dynetix AG, http://www.dynetix.ch/
67

Robust Label-Free Biosensor using BRIGHT [1] Technology
M. Wiki, F. Kehl, P. Seitz
Among the various biosensor technologies, optical biosensors are the most promising for cost-effective, sensitive and high-throughput biochemical
screening. They can easily analyse the response of a biochemical binding event without the need of any fluorescent labels. The optimized BRIGHT
technology fulfils the key requirements for optical biosensors, in particular sensor robustness and reduced time-to-result.
The requirements of biosensor instruments for research and
industrial needs today are copious, and a commercially
successful system must be capable of meeting the
expectations of a demanding user in the laboratory:
• Real-time and in situ monitoring
• Sensitive, stable and reproducible
• Detection technologies without the need of labels
• Reduction of cost, time and labor
Based on its successful WIOS principle [2] , CSEM has
developed during the past two years its BRIGHT technology
for use in label-free biosensor measurement systems. A
series of recent improvements has led to the realization of an
easy-to-use instrument, shown in Figures 1 and 2, providing
fast and accurate multi-channel dynamic measurements in
everyday lab use.
Figure 1: The BRIGHT technology is the basis of the versatile
biosensor instrument BR-8 of the CSEM startup company Dynetix
AG.
The BRIGHT technology (“Bio-layer optical Resonance
Interrogation for High Throughput”) allows sensitive, yet robust
label-free measurement of association and dissociation rates,
affinity constants, and determination of specificity of
bioreactive molecules. In the development of the BRIGHT
technology, great emphasis has been put on the expectations
of a typical laboratory user, with the goal of making his daily
work as simple, efficient and reliable as possible.
Therefore, the main focus in the development of the BRIGHTbased
biosensor instrument was its robustness, the
significantly reduced signal drift, elimination of optical and
electrical interferences, internal stray light rejection, as well as
substantial improvements of the electronics, temperature
stabilization, control software and signal processing
algorithms for efficient elimination of cross talk between the
different sensor channels.
68
Figure 2: Table-top label-free biosensor instrument BR-8 including
temperature stabilization of the sensor chip SC-8.
Due to these improvements at the heart of the BRIGHT
technology, the long preparation time prior to a measurement
has been reduced dramatically: In commercial systems of
today, biosensor chips must often be prepared in advance and
stabilized in buffer solution overnight. Conversely, BRIGHT
technology reduces the preparation time “to a fraction of an
hour”, as reported by external research institutes during tests.
As a result, several consecutive measurements can now be
performed within a short time, and long delays between
measurements can be avoided, saving labor time and
increasing throughput.
The new biosensor system BR-8 allows the measurement of
up to 8 channels simultaneously, with negligible crosstalk
between the different channels. Measurements are carried out
conveniently and reliably thanks to the disposable, versatile
biosensor chip SC-8. Since no metals are used in the
construction of the transparent SC-8 chip, interference with
the biochemical reactions under investigation is eliminated.
Due to the increasing demand for the BRIGHT-based,
versatile biosensor instrument BR-8 by industrial and research
laboratories, CSEM has created the startup DYNETIX AG [3] at
its new Research Renter for Nanomedicine, in Landquart (GR)
for the commercialization of the BR-8 instrument.
[1] BRIGHT = Bio-layer optical Resonance Interrogation for High
Throughput
[2] WIOS = Wavelength interrogated integrated optical sensor
[3] www.dynetix.ch

X-Ray Microscopy and Micrometer-Resolution Computer Tomography
J. Nüesch, P. Seitz
Recent advances in microfocus X-ray sources and high-sensitivity X-ray detection have revived interest in 2D and 3D non-destructive testing of
optically opaque biological and technical samples, offering a geometrical resolution of down to micrometers in table-top instruments.
Imaging with electromagnetic radiation in the soft and medium
X-ray region (photon energies between 1-30 keV) is an
excellent tool for the 2D and 3D investigation of optically
opaque biological and technical samples. Recent advances in
microfocus X-ray sources and high-sensitivity X-ray detection
have made it possible to realize table-top instruments for nondestructive
X-ray imaging with a geometrical resolution down
to micrometers. This resolution makes it possible, among
other things, to study the behavior of living cells, also in dense
matrices of functional biological tissues. Of particular interest
are the actions of osteoblasts and osteolcasts, the cells in the
human body which build up and destroy bone material.
A universal instrument, shown in Figure 1, has been realized
with which X-ray images of small samples with a volume of
less than 5 x 5 x 5 mm3 can be acquired. Since the X-ray
energy in the wide range of 1-100 keV can be computercontrolled,
the acquisition conditions for maximum
information-content of the signals, depending on the
thickness, the density and the elemental composition of a
sample can be optimized.
Figure 1: Universal instrument for X-ray microscopy and Computer
Tomography with micrometer resolution.
The design makes use of a novel type of microfocus X-ray
tube with a spot size of 3 µm. The magnification of the
instrument is chosen with the mechanically adaptable
constellation between X-ray spot, sample and detector
subsystem. Since the sample is placed on a high-precision
computer-controlled rotary table, the necessary data for 3D
reconstruction of the sample volume, using the techniques of
Computer Tomography (CT) can be acquired.
Two different types of X-ray imaging systems are being used
and investigated; both are based on a combination of highefficiency
scintillating material and an ultra-low-noise solidstate
digital camera. The first approach consists of gluing a
thin (a few 100 µm thick) platelet of scintillating material
directly on the image sensor. Since this complicates the
cooling of the image sensor, the second approach is currently
being concentrated on the optical imaging of the scintillator
platelet using a mirror and a high-aperture objective (f/1.2), as
shown in Figure 2. This allows not only placing the digital
camera out of the direct X-ray beam, but the overall resolution
of the system can be improved by using a geometrical
magnification and by focusing on an inner plane of the
scintillator, optimizing the contrast of the acquired images.
Figure 2: X-ray detection sub-system, consisting of a scintillator
platelet, a mirror and an ultra-low-noise digital camera with a highaperture
(f/1.2) imaging lens.
An example of a digital X-ray micrograph taken with an initial
X-ray microscopy setup is shown in Figure 3. The object
under study is a USB memory stick. The currently achieved
lateral resolution is about 20 µm.
Figure 3: X-ray micrograph of the USB memory stick offered by
CSEM to their customers and partners
The instrument is presently being improved by several means,
to make it useful for biological samples, such as living cells,
where a resolution of < 5 µm is required: Incorporation of a
digital camera with more, smaller and lower-noise pixels,
better focused optical imaging system with larger effective
aperture, as well as enhanced shielding for reduced noise.
69

SYSTEMS ENGINEERING
Mario El-Khoury
Today, the genius of diverse technology integration and
convergence enables many companies to offer innovative
products and services to their customers. New telemedicine
devices are regularly appearing. Such devices may for
example, combine GPS, sensors and communication
technologies to provide the users with better comfort and
safety levels. In the consumer market, the Nintendo’s Wii is
becoming an all-time success-story thanks to the smart
integration of motion sensors (accelerometers) in the remote
controller.
The main success factors are not the result of the vertical
mastery of base technologies, but stem from the innovative
combination and interaction of diverse but well known
technologies. The challenges associated with such
innovations include sensor fusion, miniaturisation, energy
consumption, reliability and cost reduction.
The Systems Engineering activity at CSEM is devoted to the
applied research and development of innovative solutions
involving the combination of multidisciplinary technologies,
with a particular focus on:
• Portable monitoring devices
• Communication systems
• High precision mechatronic instrumentation
In the portable monitoring devices field, CSEM has developed
and delivered to the European Space Agency (ESA) a first
prototype of a system that enables continuous monitoring of
physiological parameters. The device is aimed at studying the
adaptation of manned crews to extreme environments. It will
be worn and tested by ESA personal at the Concordia station
in Antarctica. During its validation test, the system proved to
be comfortable to wear for 24 hours. In another application
field and in the framework of a European project, CSEM is
involved in the integration of wearable electronics and sensors
in smart garments for helping rescuers during operations.
Heterogeneous electronic subsystems have been developed,
which reliably collect, synthesize and transmit the vital data
and information to a remote station.
A small and lightweight device was also developed by CSEM
in 2008 for the wellness consumer-market. The device
provides the users with a friendly feedback about their daily
physical activities, and thus helps those reducing risk factors
for chronic diseases and maintaining a healthy lifestyle.
The activities in the communication-systems field were again
focused on the one hand on Wireless Sensor Networks
(WSN) especially for environmental monitoring, and on the
other hand, on the emerging domain of Body Area Networks
(BAN). CSEM has developed a self-organized, multi-hop
network wireless sensor network, based on battery-powered
sensor nodes (WiseNode concept). In the framework of a
European project, this WSN is integrated in an infrastructure
for the detection of forest fires and floods.
Another CSEM WSN has been deployed on a cliff in the Swiss
Alps, subject to rock falls. Monitoring is done by measuring
the relative movement of rocks using extensometers. The
system has been running without human intervention for more
than a year and has confirmed its advantages compared to
wired systems. It was easier to install and does not suffer from
damage to the wires. The predicted battery life of the sensor
nodes is up to 10 years.
On the BAN side, a significant advance has been made in the
realisation of the demonstrator of a FM Ultra Wideband (FM-
UWB) transceiver. FM-UWB is a very promising solution for
BAN systems because it combines the low power and high
robustness of the UWB with the low-complexity of FM. In
parallel, a dual-patch antenna has been developed optimised
to UWB high-band systems (bandwidth from 5.5 to 9.7 GHz).
The reconfigurability and the directivity of the antenna, which
uses a RF-MEMS switch, offer interesting potentials for
energy-saving BAN or WSN.
In the Mechatronics field, CSEM has designed a new system
for the Attitude Control of Satellites (ACS). In traditional ACS,
the change in orientation of the satellite is performed through
the acceleration of three independent reaction-wheels, or by
applying torques on the gimbals holding three rapidly rotating
wheels. The proposed new system uses a unique reaction
sphere, magnetically levitated which can be accelerated
around any 3D rotation axis. The torque required for this
acceleration is exported to the satellite and is used to change
its attitude, therefore providing the required 3D torque. Cost,
footprint and weight are among the multiple advantages
expected from the new design as compared to traditional
ACS.
71

Micro-Vibration Analysis Setup for MEMS and MOEMS Characterization
J.-M. Mayor, I. Kjelberg, P. Masa, J. Babarowski
A new test station for the measurement of the resonance frequencies of micro-structures is presented. The vibrations are detected either along the
optical direction or perpendicular to it. The absolute resonance frequency is measured with accuracy better than 5 ppm (changes to 1 ppm). In
2008, the station will be equipped with a climatic and a vacuum chamber to measure the samples in a controlled environment.
Figure 1: The test station with a 100 mm wafer
Measurement of the resonance frequency of test samples with
a high accuracy is required in order to ascertain mechanical
properties of the materials used, for instance Young’s
modulus as a function of temperature.
The need to have a reliable and cost-effective system suitable
for operation in the clean room production area as quality
control during the manufacturing process was recognized.
Based on CSEM’s development, the system was built by the
company OCB (CH-Marin) with commercially available
standard mechanical blocks so that any change of the optical
configuration could easily be implemented (see Figure 1).
Particular attention has been given to the mechanical rigidity
of the system. Contrary to usual microscopes, where the fine
adjustment is done by moving the whole optical system, here
the fine adjustment is performed by a small vertical shift of the
objective only. As a matter of fact, the stability of the
observing system has been checked and found to be better
than 1 nanometer in a one hour observing time. For this
purpose, the method developed by P. Masa within the frame
of the ENCODER project [1] was used.
Microscope objectives with a magnifying power of 5 x, 10 x
and 20 x and a working distance of 39 mm also allows the test
of encapsulated microsystems. The working distance can be
further enhanced with the use of commercially available relay
lenses which permit operation of the measuring equipment
when the test sample is in a vacuum or climatic chamber (to
be developed in 2008).
The investigated test structures are expected to have quality
factors well above 1’000 therefore an excitation with amplitude
in the nanometer range, obtained with only 1 V on a PZT
stack actuator, will bring test structures into resonance with
fully detectable movement signals. The frequency response
can be obtained with a SRL lock-in, a HP spectrum analyzer
72
and a rubidium stabilized clock, directly connected to the
station.
The probe laser wavelength is above 650 nm so that the color
rendering of the microscope is not affected by the dichroic
beam splitter in the observation path of the camera: any
defect of the test sample is clearly recognizable on the
display.
The detection of the movement can be measured either along
the optical direction (perpendicular to the wafer plane) or
perpendicular to it (in the wafer plane).
• For the detection of the movement in a horizontal plane
the investigated part must have a sharp edge on which the
laser beam is focused. Any movement of the edge will
change the amount of light reflected or transmitted.
• For the detection along the optical axis a surface of
reasonable optical quality is needed. Then an optical fiber
is put at the image point of the laser spot. Any deviation in
height will affect the size of the spot and thus the quantity
of light transmitted into the optical fiber.
With both configurations absolute resonance frequencies of
test samples and of microsystem structures were determined
with accuracy better than 5 ppm. Resonance frequency
change (for instance with temperature) can be detected with a
sensitivity down to 1 ppm by measuring the phase difference
between the excitation and the position signal.
Figure 2: Mechanical response of a microstructure after a shock
As the optical signal is a direct position signal the station can
monitor aperiodic movements as well. An example is depicted
in Figure 2, where the microsystem was subjected to a shock
by a mechanical impact on the sample holder. Two impacts
corresponding to the moving part of the sample touching the
mechanical stop, then coming back to the equilibrium position
with oscillations at its resonance frequency can clearly be
seen. The damping of the movement can be also determined.
The equipment was financed by the Hans Wilsdorf foundation.
CSEM thanks them for their support.
[1] P. Masa, et al., “Encoder – Nanometric Optical Absolute Position
Encoder”, in this report, page 14

Clinical Validation Results of the Long-Term Medical Survey System
O. Chételat, A. O'Hare, P. Pilloud, J-M. Koller, S. Droz, A. Ridolfi, P. Theurillat, P. Renevey, J. Solà I Caros, O. Grossenbacher
The paper describes the clinical validation of a physiological multi-parameter monitoring system made by CSEM for ESA. Results of the validation
showed that the system fulfils its purpose. The real conditions of the validation also hinted at further potential enhancements.
The European Space Agency (ESA) commissioned CSEM to
design, build, validate and deliver one fully operational ground
prototype of a system (LTMS2) measuring physiological
parameters. The system was shipped and will be used during
2008 at Concordia station (www.concordiastation.com) in
Antarctica to study the physiological adaptation of manned
crews to remote, isolated and extreme environments. The
underlying long-term objective for ESA is to obtain experience
in the field which will be used in preparing a possible manned
mission to Mars around the year 2030. This paper describes
the clinical validation of the system performed in December
2007 on volunteers at the Emergency Care Unit of the
University Hospital of Bern (Inselspital).
LTMS2 is composed of an ‘ambulatory unit’, a ‘stationary unit’
and some accessories, as well as acquisition, processing,
archiving, and visualization software. The ambulatory unit (see
Figure 1) simultaneously measures − in an unobtrusive,
comfortable and modular way − ECG (Electrocardiograph),
respiration, pulse oximetry (at the earlobe or fingertip),
activity/posture, core body temperature (at the armpit or ear
canal) and blood pressure (with a cuff at the arm). The data is
recorded for 24 hours while the subject performs his or her
usual daily tasks. During setup or modification of the
configuration, the signals can also be visualized online.
Figure 1: The ‘ambulatory unit’ of the LTMS2 system
The ambulatory unit integrates commercial sensors with
CSEM technology. In particular, the ‘electrode’ shown in
Figure 2 is actually made of two active dry stainless steel
electrodes measuring ECG and impedance, as well as an
acceleration sensor (used for activity and noise removal). The
data is digitalized in the electrode and transmitted to a
centralized data logger.
Figure 2: The ambulatory unit ‘electrode’ comprising analogue and
digital electronics to measure ECG, impedance and activity
The stationary unit measures the body weight and
composition (fat mass, water and muscle mass). All data is
transferred to a laptop where it is processed further to
obtained secondary signals such as ECG parameters (heart
rate, heart rate variability, ST-segment amplitude and
duration, QT-index − see Figure 3) or activity classification
(resting, walking, running, lying or standing). All signals are
then transferred to a database for storage where they can be
remotely accessed by a medical doctor (MD). Special
mechanisms ensure that no data can be lost, accidentally
erased or viewed by unauthorized people. The visualization of
the signals is multi-scale and several sessions can be
displayed on the same time axis. Out-of-boundary sections for
any signal are marked and can be quickly accessed.
Figure 3: The different parameters of a typical ECG wave
The LTMS2 system was designed, built and tested according
to the European directive #93/42/ECC and follows the relevant
medical standards, especially EN60601-1 and EN60601-2-47
for CSEM ECG electronics. However, the system is not CE
marked (even though many of its components are), because
the intended use is for clinical trials in Concordia.
Nevertheless, after having obtained the ethical committee and
Swissmedic authorizations, and fulfilled other requirements of
the norm ISO14155, the system was clinically validated by
Prof. Dr. MD S. Jakob at Bern hospital.
The principle of the validation was to test the system on a few
healthy volunteers in a controlled environment and to compare
73

the signals with a reference to standard hospital devices. In
addition, the clinical validation was a final test by a third party
to check that all variables are recorded, downloaded and
displayed as described in the user manual, as well as to
medically assess the ECG quality regarding the identification
of the ECG P-, QRS-, and T-waves (see Figure 3).
Figure 4: Typical signals obtained and visualized by the LTMS2 system (from the clinical validation)
The validation was performed on three volunteers in three
sessions of 18 hours and one of 24 hours. All sessions
comprised ‘normal’ daily activities such as office work, walking
around, jogging and night sleeping.
The validation clearly proved that the system is comfortable to
wear for 24 hours and can record data for this period, process
the data and visualize a large number of physiological
parameters in perfect synchronism with time. The accuracy of
the parameters does not, however, always match the
reference. While the bias was negligible for heart rate, oxygen
saturation and respiratory rate, LTMS2 underestimated
temperature by 1 °C and overestimated systolic and diastolic
blood pressure by roughly 10 mmHg, and mean blood
pressure by approximately 5 mmHg. The relatively bad
accuracy of the blood pressure is surprising since for this
parameter LTMS2 simply provides a digital interface to a
CE-marked commercial device.
Motion artifacts were sometimes a problem for oxygen
saturation measurement. This is easily explained though:
during the validation, the reference device was placed at the
fingertip whereas the LTMS2 sensor was placed at the
earlobe (less obtrusive but more subject to artifacts). A similar
explanation holds for ECG and related parameters such as
heart rate that are sometimes altered by artifacts. In this case,
one has to take into account that the reference used a threelead
system, while LTMS2 is limited to one lead. Cross
74
Figure 4 shows a typical display of signals measured during
the clinical validation. The ECG P-, QRS-, and T-waves are
clearly identified and the ST, QT, and QRS segment correctly
marked. The figure also shows the heart rate, respiration rate,
ST amplitude and duration, and the QT index.
checking between leads is therefore impossible in LTMS2,
which increases the risk of being deceived by artifacts.
In LTMS2, the activity signal is picked up at the electrode,
while the reference used a watch-like device. Despite this
location difference, LTMS2 and the reference device showed
similar actigraphs. The activity and posture classification was
in accordance with the situations specified by the experiment
protocol (no reference was available for these parameters).
In conclusion, the LTMS2 system has been proven
operational in real conditions. Taking into account the
differences between the location and technology used for the
measuring of the physiological parameters, the LTMS2
system accuracy has been validated. However, a future
enhanced version of the LTMS2 prototype should include
additional means to automatically detect and reject more
artifacts. Other foreseen improvements include more
integration and accuracy, in particular for core body
temperature, oxygen saturation and blood pressure. CSEM is
already conducting research projects on these challenging
topics. Many subsystems of LTMS2 − released from some of
the stringent requirements of the ESA needs − can be readily
converted to commercial applications in several domains,
including physiological monitoring in sport and high-altitude
activities, in firefighting and life-threatening situations, in home
care and telemedicine, or in physiological studies.

ActiSmile – A Portable Biofeedback Device on Physical Activity
B. Gros, J. Solà I Caros, P. Theurillat, J. Krauss, U. Mäder • , H. Buchholz ••
Together with the Swiss Federal Office for Sports (BASPO) and the company ActiSmile SA CSEM has designed and developed a portable
biofeedback device to continuously monitor the physical activity of its user. The key technology resides in sophisticated signal processing methods
for multi-axis accelerometer sensor systems, including modern feature extraction, classification algorithms and low-power implementation on a realtime
platform.
Motion is an important modulator of vital human organic
functions such as respiration, heart cycle, blood oxygen
saturation. Physical activity is viewed as an important
component of a healthy lifestyle and the relationship between
physical activity and several known risk factors for chronic
diseases are well-known. Important information about human
health is expressed in human motion during day and night,
such as the daily relative percentages of walking or running
with respect to resting. These relative percentages can be
used as indicators of potential psychological disorders or
physiological pathologies. Accelerometry-based activity
monitors are widely used to capture objective information on
patterns and levels of physical activity. Although data
collection is relatively easy, data reduction and data
processing are challenging topics.
The company ActiSmile SA has mandated CSEM to design,
develop and implement a portable biofeedback device to
continuously monitor and promote the physical activity of its
user. The classification approach relies on the signals of a
multi-axis acceleration sensor system which are projected to
the breast vertical axis of the subject. Feature extraction is the
essential part of the processing prior to any classification task.
Features depend on the signals and the choice of a pertinent
small size of feature set improves the intersubject
classification accuracy. The design of the feature space in the
classification machine takes into account the final desired low
complexity algorithm in order to target a low-power and
portable application on a real-time platform. For this reason,
features derived from frequency or any other eigenfunction
transformed domain has been eluded. An extensive study on
the physiology of human motion has allowed the development
of a new set of proprietary features derived from the temporal
domain. The features are fed to classification stage. Being
aware that the final applications may require different
classification resolutions, a decision tree has been chosen as
the most appropriate classification strategy.
The ActiSmile device performs in real time the data
acquisition, feature extraction, classification and high-level
interpretation routine tasks. The output of the processing
stage corresponds to an activity class tag (namely: lying,
standing, walking, running), which is calculated every
5 seconds and stored within the FLASH memory of the
portable ActiSmile device. A high-level interpretation algorithm
calculates with the number of stored activity class tags the
user feedback. A SMILEY is fed back and displayed on the
LCD of the ActiSmile device, if the user has performed the
defined minimal physical activity according to the guidelines of
the World Health Organisation (WHO). Figure 1 shows the
portable ActiSmile devices which are worn either with a clip on
the thorax of the user or at the belt, or around the neck with a
lanyard. The ActiSmile device can be recharged via a
standard USB cable.
Figure 1: Portable ActiSmile device with USB version (left) and
wireless version (right).
The transmission of the stored activity class tags to a data
validation software can be performed either via an USB link or
wireless with a Bluetooth version, as shown in Figure 1. The
transmitted data can be validated under a Windows based
data visualization and calibration software. The trends of the
performed physical activity can be visualized on a daily,
weekly and monthly basis as shown in the graph of Figure 2.
Moreover, the data validation software provides a calibration
tool to program and individualize the portable ActiSmile device
with the personal data age, weight, sex and fitness level. The
calculation of the SMILEY feedback is adapted accordingly.
Figure 2: Windows based data visualization software, with the graph
of the performed daily physical activity (x-axis: time; y-axis:
percentage of performed physical activity).
The verification of the correct interpretation of the performed
physical activity with the ActiSmile devices has been validated
by the Swiss Federal Office of Sports. A pre-series of the
ActiSmile product was launched in October 2007 and a further
product enhancement is planned during 2008.
•
Institute of Sports Sciences, Federal Office of Sports (BASPO),
CH-2532 Magglingen; (www.baspo.admin.ch)
••
ActiSmile SA, Rathausstrasse CH-6340 Baar;
(www.actismile.ch)
75

Prediction of Neurocardiovascular Events
R. Vetter, N. Virag •
In order to improve acceptability and quality of life related to a medical diagnostic test, CSEM developed in a joint collaboration with Medtronic
Europe a system based on computer supported prediction of the test outcome. The results of the retrospective study on 1155 patients are very
promising and show that if the diagnostic test was stopped at the instant of event prediction only five percent of the patients would have had to
experience the traumatic neuro-cardiovascular event associated with a positive test outcome.
Patients with unexplained neuro-cardiovascular disorders
often represent diagnostic dilemmas due to the difficulty to
gather the pre-current signs of significant events. The rarity of
such events brings about that limited time period monitoring
using external Holter may be ineffective and not record the
pre-current signs and cause of the disorders. More advanced
monitoring devices such as implantable loop recorders may
gather the pre-current signs and causes of the disorder but
only if a dedicated automatic event detection exists.
Nevertheless, such devices require invasive procedure and
thus cause increased diagnostic costs. To approach this
problem, diagnostic medicine designed dedicated
experimental protocols which will provoke the specific neurocardiovascular
events through external controlled stimulus
and conditions. The inconvenience of these approaches
consists in the fact that the patient has to experience the
neuro-cardiovascular event during the diagnostic assessment.
This is often traumatic and is a reason why some patients
prefer not to undergo such a test.
As an example, tilt table testing is recognized as a standard
test to diagnose vasovagal syncope and establish the neurocardiovascular
dysfunction. The test is illustrated in Figure 1.
After 5 minutes supine rest, the patient is tilted to a 60 degree
head-up position. If symptoms do not develop after 20 min of
tilt, sublingual glyceryl trinitrate is administered to further
provoke syncope. The test ends successfully if syncope
develops or is stopped unsuccessfully after 35 min. Thus,
each successful tilt test allowing an establishment of the
neuro-cardiovascular dysfunction and yielding further medical
insights ends with a traumatic fainting of the patient.
In order to make this test more acceptable to the patient,
shorten the tilt testing experience and decrease the diagnostic
costs, a method which allows an early prediction of a
successful outcome of the tilt test [1] has been developed. The
algorithm exploits the trend of blood pressure, the trend of the
heart rate and an indicator of the autonomic nervous
modulation to continuously process a cumulative risk of the
positive outcome of the tilt test. The algorithm yields an alert
when a threshold is crossed. This suggests that the tilt table
test will be positive, that syncope will occur in very soon and
that the test should be stopped to avoid the traumatic
experience of fainting for the patient.
The performance of the algorithm was assessed on a large
control database of 1155 patients where tilt table tests were
conducted to their end. The successful outcome of the tilt
table test was predicted in 719 of 759 patients (95%) whereas
29 false alarms were generated in 396 unsuccessful tilt table
tests. On average the successful outcome was predicted 60
seconds before fainting leaving sufficient time to stop the
experience before the traumatic outcome.
76
In other words, if the test had been stopped at the alert
processed by the computer, out of 759 patients only
40 patients would have had to experience the traumatic
fainting experience engendered by vasovagal syncope while
for 719 patients the establishment of the autonomic
dysfunction would have been performed without traumatic
psychological stress.
The proposed system may open a novel area in diagnostic
medicine where traumatic events due to systemic dysfunction
would not have to be experienced to further establish and
assess a pathological situation. The clinical validity of the
proposed application of prediction of vasovagal syncope is
limited due to the retrospective nature of the study. However,
a prospective clinical study is currently being designed.
In conclusion, computer supported sensing and processing of
vital signals in a diagnostic protocol could increase the
acceptability of the tilt test protocol and improve the patient
quality of life. In medicine there are few parallels for which
standard tests are replaced by mechanisms predicting
outcomes midway through a laboratory study. The present
development concerns a first step in such a process.
Figure 1: Illustration of tilt table test setup used in medical diagnostic
to establish neuro-cardiovascular dysfunction together with the
developed system predicting the test outcome.
The work was partly funded by the CTI Medtech Initiative and
CSEM would like to thank them for their support.
•
Swiss R&D Medtronic Europe
[1] N. Virag, R. Sutton, R. Vetter, T. Markowitz, M. Erickson,
“Prediction of vasovagal syncope from heart rate and blood
pressure trend and variability: Experience in 1,155 patients”,
Heart Rhythm, vol. pp. 1377-1382, November 2007.

Reaction Sphere for Attitude Control
O. Chételat, L. Rossini, I. Kjelberg, S. Droz, L. Giriens, E. Onillon
CSEM has developed a new concept for attitude control of satellites, within the frame of an ESA project, associated with Maxon, RUAG and HEVS.
An Attitude Control System (ACS) traditionally needs a
minimum of three reaction wheels. The orientation of the
satellite can be changed by reaction at the acceleration of the
appropriate wheel. Another traditional approach is to use a
control moment gyro consisting of a rapidly rotating wheel
held by gimbals. Applying torques on the gimbal joints
changes the satellite orientation.
The proposed approach is to use one unique reaction sphere
playing both the role of ‘reaction sphere’ and − as the angular
velocity of the sphere increases − the role of ‘control moment
gyro’. The sphere is held in position by magnetic levitation and
can be accelerated about any rotation axis by a 3D motor. The
torque required for this acceleration is exported to the satellite
and is used to change its attitude. Thus, the reaction-gyro
sphere is an actuator able to produce a 3D torque.
The concept of reaction sphere is not new. However, the
limitations of existing technologies and engineering
capabilities have prevented reaction gyro spheres from being
developed. The difficulty is clearly in the 3D motor, the
magnetic bearing, and its combination. Recent advances in
technology and especially in high-power Space-qualified
processors give a totally new chance to the concept.
A study has been performed to select the rotor and stator
configurations. A synchronous motor configuration, with an 8
pole permanent rotor and a 20 pole stator has been selected,
as depicted in Figure 1.
The number of stator poles corresponds to a regular
distribution of poles on a sphere, without singularities. The
permanent-magnet motor has been selected for efficiency
reasons, for the reduced complexity of its possible controller
as well as its linearity (bearing and force control can be simply
added). This concept has many advantages compared to
others and an international patent application has been filed.
Figure 1: Selected configuration
A Matlab/Simulink model of the Reaction Sphere, based on
the selected concept, has been developed. The model is
based on a state space approach, the input of which being the
20 coils voltages and the outputs are the components of the
torque vector. This model requires the calculation of the 3D
motor constant (linking currents to force and current to toque)
as a function of the sphere orientation. This model has been
used to develop a control algorithm, based on PI controllers.
A demonstrator is to be produced. The rotor will have an 89
mm radius and the external radius will be 103 mm.
The demonstrator will be equipped with three position sensors
from uEpsilon, 3 force/torque sensors from Kistler and flux
sensors. The flux sensor will be used to determine the sphere
orientation.
A custom electronic with 20 coil amplifiers will be developed to
drive the Reaction Sphere, This amplifier also serves as the
interface to a dSpace 1005 board on which the control
algorithm will be implemented.
At the end of the year 2007, the design was finished and the
building of the demonstrator is under progress within the
frame of an ESA project that is to end in October 2008.
Figure 2 presents a drawing of the demonstrator being built,
with all its instrumentation around for its validation.
Figure 2: Reaction Sphere demonstrator
77

Continuous Arterial Blood Pressure Monitoring: Can the Cuff Be Got Rid of?
J. Solà I Caros
A novel family of portable arterial blood pressure monitors is under development based on the multiparametric sensing of the cardiovascular
function. Current status of research, initial experimental results and future guidelines are described here.
In clinical practice, an ever-lasting technology in the
assessment of arterial blood pressure dominates the
landscape: the so-called auscultatory technique introduced in
1905 by Korotkoff: a well trained operator places a
stethoscope over a distal artery and interprets the sequence
of sounds that occur while a cuff placed above the artery is
deflated. Although such an approach retains a secure position
in the surgery, the occasional measurements taken in this
manner can be unusually high (white coat effect) or low,
leading to false diagnoses. Consequently some individuals
may receive unneeded treatment and those actually needing it
can be lulled into a false sense of well-being hence elevating
their risk of cardiovascular disease.
Alternatives to the auscultatory technique do exist in the field
of ambulatory monitoring of blood pressure: most
epidemiologic research studies rely on automatic inflation
cuffs placed either over the brachial or radial arteries e.g. the
devices that one might acquire in a pharmacy nowadays.
Although relatively accurate, this so-called oscillometric
technique does not match with the philosophy of portable
continuous monitoring in two senses: on the one hand the
measurement periodicity must be commonly set to 30 minutes
because of the discomfort and pain associated with each
inflation event, providing thus only a partial picture of the
blood pressure evolution. On the other hand, each
measurement alters the life-style of the user and thus modifies
the blood pressure profile, especially at night.
However, the need for a continuous cuff-less blood pressure
monitor is continuously increasing in the fields of e.g.
pharmacology, clinical practice and sports.
A new family of cuff-less blood pressure monitors based on
the optical and electrical sensing of a set of cardiovascular
parameters is being explored at CSEM. The strategy consists
of non-invasively tracking the evolution of those hemodynamic
components that play a role in the establishment of the fluidic
pressure in the arteries, and from them, obtain an indirect
blood pressure estimate. From a fluidic perspective, two
hemodynamic components must be considered: the cardiac
output, i.e. the flow of blood from the left ventricle to the
systemic vessels, and the total peripheral resistance i.e. the
resistance, in a Poiseuille sense, that the systemic vessels
oppose the cardiac output.
The metrological strategies adapted inherit the know-how in
multiparametric cardiovascular monitoring acquired during
earlier research at CSEM. At the current stage an estimate of
78
cardiac output is being assessed through the statistical signal
processing of bioimpedance measurements. Bioimpedance
depicts the measurement of the electrical potential differences
that are generated across the thorax of an individual through
the injection of low power AC currents on the skin surface. For
the assessment of total peripheral resistance, a new approach
based on the probabilistic information processing of infra-red
tissue absorption and bioimpedance data has been developed
and patented [1] . Both sensing techniques are inconspicuous
and imperceptible by the subjects. The approach partly relies
on the measurement of the wavefront propagation velocity of
pulse waves through the arterial tree, the so-called pulse
wave velocity.
Figure 1 shows the results of an in-vivo study realized at
CSEM labs. During the experiment, the mean arterial blood
pressure of a subject was modified while several vital
parameters were monitored with a reference device and the
CSEM prototype. In this particular experiment the novel
approach successfully tracked the variations of mean arterial
blood pressure induced to the subject.
MAP [mmHg]
160
140
120
100
80
60
CO [l/min]
TPR [mmHg.s/mL]
8
6
4
2
1
0
0 5 10
Time [min]
15 20
PORTAPRES
CSEM
Figure 1: Experimental dynamic cardiovascular responses estimated
during a period of 25 minutes by a reference device (PORTAPRES)
and CSEM technique.
Returning to the initial question of being able to achieve
continuous blood pressure monitoring without the cuff, the
results obtained by CSEM biomedical sensing technology
suggest this goal may be achieveable, at least under certain
constraints. The research is still in progress.
[1] J. Solà I Caros, “Method for the continuous non-invasive and
non-obstrusive monitoring of blood pressure”, EP07123934.7,
2007

WISE – Wireless Solutions for the Aeronautics Industry
A. Hutter, B. Perrin, L. von Allmen, C. Kassapogou Faist
This report is a summary of the work carried out under the European WISE project. This project investigates wireless solutions for the air industry.
The focus of this article is on the evaluation and implementation of low-power protocols.
The European WISE project [1] is a research activity that is
intended to strengthen the competitiveness of the European
air industry in the wireless domain. As such, the project
investigates wireless technologies together with autonomous
powering sources for aircraft sensing and monitoring systems.
Industrial partners from the air industry include
EUROCOPTER and DASSAULT as well as Messier-Bugatti
and the EADS research centre.
Within the project consortium CSEM is the expert partner for
the following two domains:
• wireless solutions for difficult propagation environments
• low-power implementations for wireless solutions
For the first domain, a magnetic solution for a wireless
oxygen-bottle pressure-readout system has been designed
and implemented. The major difficulty for this application was
to guarantee transmission through metal shielding with only
tiny holes. Concerning the second domain, CSEM expertise
was required for the wireless replacement of the helicopter
turbine air-intake temperature sensing system. The remainder
of this article will focus on the description of this application
and the implementation of the low-power wireless sensor.
Figure 1: Air-intake area of helicopter turbine and placement of the
temperature sensor
High precision temperature measurement (0.1° C) of the
incoming air stream is required to guarantee optimum and
efficient turbine operation. The current solution uses a PT100
temperature sensor located in the head of a rod placed inside
the air-intake section of the turbine, see also Figure 1. The
read-out electronics is placed in the engine compartment,
where the temperature is relatively high. Due to the potential
temperature variations along the cable, the measurement
error can be higher than the required precision.
The investigated replacement system foresees a wireless
sensor unit that is located at the bottom of the temperature rod
in the engine compartment. To guarantee autonomous
operation, the sensor is equipped with a magnetic micro-
generator that exploits the vibrations of the helicopter. The
micro-generator should deliver up to 10 mW continuously,
which results in a maximum current constraint of 5 mA when
operating at 2 V supply voltage.
For the evaluation of the wireless transmission protocol
options, a graphical user interface was developed, see also
Figure 2. This tool allows the rapid visualisation of the impact
of different protocol parameters. For the WISE application, a
beacon-enabled network with a beacon interval of 491 ms was
selected in order to guarantee the required delay constraints.
Figure 2: Graphical user interface to evaluate protocol trade-offs
Initial implementation results show that an average current of
1.7 mA is required for the transmission system, see also
Figure 3. These initial results do not yet include the power
consumption for the signal acquisition circuit. It is anticipated
that the latter draws a maximum current of 1 mA, which
results in an average current of 0.1 mA for 10% duty cycling
(100 Hz sampling frequency). Therefore, with an estimated
average current of 1.8 mA, which is equivalent to
3.6 mW@2V, it is expected to meet the power constraint
originating from the micro-generator.
Figure 3: Implementation results with signal acquisition emulation
[1] Project web-site: www.wise-project.orghttp://www.wiseproject.org/
79

UWB Antenna with Improved Bandwidth and Spatial Diversity using RF-MEMS Switches
Q. Xu, L. Petit, J. R. Farserotu
An UWB dual patch antenna with optimized bandwidth from 5.5 to 9.7 GHz was developed. Together with a RF MEMS based switch combining
circuit, the UWB antenna allows construction of a reconfigurable unit that provides multiple-direction radiation.
Within the project e-SENSE, CSEM has undertaken R&D on
energy efficient FR solutions for Wireless Sensor Network
(WSN). To successfully address the different scenarios and
enhance the overall system performance, a very promising
option is to add more functionality to the antenna subsystem,
and focus on pattern reconfigurability of the UWB antennas.
The motivations to address radiation pattern reconfigurability
are the following:
• Range extension
• Direction Of Arrival (DOA) estimation
• Enhanced coexistence (Multiple users, multipath rejection)
UWB antenna design – a structure of stacked and notched
dual-patch has been adopted to achieve the bandwidth
enhancement. Parameters, including the size of the patches,
the slot length, the microstrip feed position, the spacer
thickness, as well as the dimensions of the notches, that
impact the bandwidth performance have been optimized
simultaneously in simulations. The enhanced impedance
matching bandwidth ranging from 5.5 GHz to 9.7 GHz has
been achieved and has shown good agreement with
measured results (Figure 1).
80
S11 Mag [dB]
0
-5
-10
-15
-20
-25
-30
Measurement
Theoretical computation
-35
4 5 6 7 8 9 10 11 12
Frequency [GHz]
Figure 1: Measured and simulated impedance bandwidth
RF-MEMS combining circuit – a switch combining circuit has
been developed and is presented in Figure 2. RF MEMS for
reconfigurable antennas and beam forming networks (BFN)
exhibit outstanding performances in terms of linearity, low
power consumption and RF performances. The combination
of several UWB antennas with a RF-MEMS switch based feed
network in order to achieve both spatial diversity and powerefficiency
at UWB frequencies has thus been addressed. The
antennas and the switch combining circuit have been
designed, tested and optimized separately. This solution has
more flexibility in terms of the gain and the pointing directions.
The circuit by itself consists of three cascaded COTS RF-
MEMS devices as well as associated components (bias
resistance, feed capacitance, charge pump capacitance, logic
circuitry). Because of the particular nature of RF MEMS
devices, which are electrostatic actuated micro
electromechanical (MEMS) structures, the design, assembly
and test of the RF-MEMS based circuit has been undertaken
taking into account consideration for handling (Electrostatic
Discharge (ESD) sensitivity) and assembly (ultrasonic
cleaning/mechanical vibration sensitivity). The designed RF-
MEMS based switch combining circuit showed very good
isolation between the different antenna ports for higher
diversity efficiency along with very low power consumption.
Measured radiation patterns of the UWB antenna array using
the RF-MEMS switch combing circuit are shown on Figure 3.
Figure 2: Left - Switch combining circuit. Right - mounted antennas
270
300
240
330
210
0 [dB]
-10
-20
-30
-40
0
180
30
60
120
150Antenna3-on
Antenna4-on
Figure 3: Achieved two radiation directions using RF-MEMS
Conclusion - An UWB dual patch antenna with optimized
bandwidth was developed. The enhanced bandwidth from 5.5
to 9.7 GHz covers the frequency band required by
communications using UWB in the high band. The antenna
diversity providing two beams enabled by a RF-MEMS switch
has been demonstrated. The reconfigurability and the
directivity of the antenna offer interesting potentials for
energy-saving in a simultaneous communication scenario of
WSN.
This work was partly funded by IST project e-SENSE. CSEM
thanks them for their support.
90

FM-UWB – A Low Data Rate (LDR) UWB Approach with Short Synchronization Time and
Robustness to Interference and Frequency-Selective Multipath
J. F. M. Gerrits, J. R. Farserotu, M. Hübner, J. Ayadi
Constant-envelope FM-UWB is a true LDR (< 100 kbit/s) UWB system. Instantaneous despreading in the receiver allows for rapid synchronization.
The robustness to interference and frequency-selective multipath make this system a good choice for robust LDR Body Area Network systems.
Ultra Wideband (UWB) communications are poised to enable
short-range applications, such as remote health monitoring (ehealth)
and home or office automation.
Body Area Networks (BANs) [1] are potential candidates for
UWB since the low radiated power of the UWB transmitter
enables low DC power consumption yielding long battery life
and the possibility to use energy scavenging. Size and cost
constraints require a low-complexity approach that allows
multiple users sharing the same RF bandwidth, and offers
robustness to interference and frequency-selective multipath
propagation conditions.
Constant-envelope FM-UWB uses double FM: binary FSK
followed by high modulation index analog FM implementing
analog spreading. The FM-UWB signal is characterized by a
flat spectrum and steep spectral roll-off.
Due to the instantaneous despreading in the receiver,
synchronization time is limited only by the bit synchronizer in
the FSK demodulator. Figure 1 shows measurement results
taken in a 62.5 kbps FM-UWB system operating at 4 GHz.
Transmission starts at the rising edge of the TX_ENABLE
signal. On the receiver side, the raw data RXD is available
almost instantaneously, whereas the bit synchronizer circuit
determines the overall receiver synchronization time. From a
synchronization point of view, the FM-UWB system behaves
like a narrowband FSK system.
Figure 1: Measured FM-UWB receiver synchronization time.
Interference from in-band UWB users benefits from the
receiver processing gain which is equal to the ratio of RF and
subcarrier bandwidth
G
PdB
= 10 log
10
⎛ B
⎜
⎝ B
RF
SUB
⎞
⎟
= 10 log
⎠
10
⎛
⎜
⎝
2Δf
⎞
( ) ⎟ RF
β + 1 R
SUB
In a 100 kbit/s LDR system with a RF bandwidth of 500 MHz a
processing gain of 34 dB is obtained. As a result a 100 kbps
FM-UWB radio can tolerate a 21 dB stronger FM-UWB
interferer. Simulations have confirmed these values and also
⎠
show that Impulse Radio and MBOFDM interference up to
15 dB stronger than the FM-UWB signal can be dealt with.
FM-UWB signals are robust to frequency-selective
multipath [2] . Figure 2 shows MATLAB simulation results of the
RF sensitivity improvement for 1000 realizations of the IEEE
CM4 (strong non line-of-sight) channel. The graph in the
upper part of the figure shows the RF sensitivity improvement
for each channel realization. The histogram in the lower part
of the figure shows the distribution of the receiver sensitivity
improvement. The average and median value both equal 0 dB
meaning that 50% of the strong non line-of-sight channels
yield a performance improvement. The worst-case sensitivity
degradation is only 2.5 dB.
Straightforward by its principles, FM-UWB constitutes a LDR
UWB communication system highly robust to interferences
and multipath.
Figure 2: Sensitivity improvement in CM4 channel.
[1] J. F. M. Gerrits, J. R. Farserotu, "FM-UWB: A Low Complexity
Constant Envelope LDR UWB Communication System", IEEE
P802.15 Working Group for Wireless Personal Area Networks
(WPANs), July 2007, San Francisco, California, USA,
IEEE802.15-07-0778-040ban,
http://www.ieee802.org/15/pub/Sgmban.htm
[2] J. F. M. Gerrits, J. R. Farserotu, J.R. Long, "Multipath Behavior
of FM-UWB Signals", Proceedings of ICUWB2007, Singapore,
September 2007
http://www.wise-project.org/
81

A Wireless Sensor Network for Fire and Flood Detection at the Wild and-Urban Interface
C. Kassapoglou Faist, P. Nussbaum
CSEM develops a wireless sensor network as part of a sensing and computing infrastructure for the detection and assistance in crisis management
during natural hazards (forest fires and floods). Vision sensors as well as low-cost, in-field sensing elements are integrated in the network.
In spite of all technical progress mankind has achieved,
natural hazards escape its control. Nonetheless, early
detection, combined with genuine crisis management are
essential in limiting the extent of disaster. The ability to
monitor the evolution of relevant physical quantities
throughout an area is a key element in this respect and, in the
last few years, wireless sensor network technology has
rendered this task feasible and affordable. CSEM, active in
this field, participates in the EU project SCIER, which aims to
improve the design and realization of a sensing and
computing infrastructure for environmental risks, particularly
focusing on forest fires and floods.
The project combines wireless network technology with data
fusion schemes and environmental models in order to provide
an end-to-end system that detects the occurrence of a natural
hazard and supports the authorities during intervention. Its
user requirements are tailored on the problematics of the wild
and-urban interface (areas at the border of urban zones,
where isolated properties intermix with wild land). SCIER
involves both publicly and privately owned equipment, offering
to landlords the opportunity to subscribe in fast, localized
alerts.
Figure 1: SCIER sensing system
The sensing system is composed of in-field as well as out-offield,
vision sensors (Figure 1). They are spread throughout
the monitored area and periodically report measurements that
are collected through a number of access points (private or
public) and reach the computing subsystem. This information
is subsequently assessed, stored and processed by data
fusion schemes, in order to decide whether anything is
abnormal. In case of hazard detection, alarms are issued,
both to the public authorities and to local property owners, and
execution of the appropriate environmental models is
triggered, in order to predict the evolution of the hazard and
other related risks. Possibly, the density of sensors is
increased through new deployments during the crisis. The
environmental models are fed with geographic information
from the SCIER GIS component and periodically confront their
prediction to actual measurements provided by the sensors.
CSEM is responsible for the sensing system. Battery-powered
sensor nodes form a self-organized, multi-hop network. They
are composed of a few sensing elements and a wireless
communication unit, developed at CSEM (WiseNodeTM concept) and based on a MSP430 micro-controller and a
82
Chipcon CC1100 radio transceiver. Since the batteries are to
last for months or even years, the node design follows severe
energy-saving techniques: multi-hop communication, use of
energy-efficient protocols and in particular the CSEM
WiseMacTM , operation in duty cycles with the nodes put in
sleep mode most of the time. In SCIER, the deployed nodes
are fixed, but the sensor network must support the hot
deployment of new nodes (during a crisis, for instance) or the
loss of some of its nodes (which may be a significant piece of
information).
The in-filed sensing elements are relatively cheap, commercial
components. The Davis anemometer is used for wind speed
and direction, the Davis and Technoline WS9004IT rain
collectors for rainfall levels, the Sensirion SHT11 for
temperature and relative-humidity measurements. The latter
was assessed at controlled fire experiments that were
conducted within a wind tunnel at MAICh, in Greece. The
nodes are packaged in watertight, UV-resistant boxes for
protection against natural elements, with the sensors fixed
outside the box.
An important innovation feature in SCIER is the integration of
vision sensors in the wireless sensor network. Vision sensors
are dedicated to monitor the field in order to detect an event
and report on this result (a feature). Among the different
possible events, occurrence of smoke by day and flame by
night have been selected (Figure 2). A spatial correspondence
between the detected events and the location will be
implemented to enable data fusion at sensor level.
Figure 2: Vision sensor firmware architecture
Development of the SCIER sensing system is about to be
completed, offering a low-cost solution for the collection of
spatially distributed information. In 2008, the SCIER concept
as a whole will be tested at full-scale field trials in Portugal,
France, the Czech Republic and Greece.
The project partners are Epsilon International SA (GR),
National and Kapodistrian University of Athens (GR), DHI
Hydroinform A.S. (CZ), National Agricultural Research
Foundation (GR), CSEM (CH), Group 4 Security Services
(GB), Greek Research and Technology Network (GR), Centre
d'Essais et de Recherche de l'ENtente (FR), TECNOMA S.A.
(ES), Associação para o Desenvolvimento da Aerodinâmica
Industrial (PT).

Exploiting Directive Antennas for Wireless Sensor Networks
L. von Allmen, P. Dallemagne, Q. Xu, J. R. Farserotu
CSEM identified and characterized a number of applications using wireless sensor networks that would benefit from directive antennas. The goal is
to reduce the power consumption of the communication system, while preserving or even improving the quality of service.
CSEM is investigating energy saving techniques using
directive antennas for wireless communication devices [1] in
specific applications. The use of directive antennas offers the
potential for improved overall system performance. For
example, one measure of performance is the environmental
impact of the radio-communication system, which may be
reduced by lowering the emissions, which in turn translates
into power savings, as well as, improved coexistence. Further,
the use of directive antennas offers the potential for reducing
the overall power consumption of the communication system;
especially, in high density networks, where the number of
transmitting devices can be large. Reducing the radiated
power also improves spatial re-use, global reduction of the
electro-smog and implicit improvement of the end user privacy
by focusing and segmentation. Ultimately, this relates to the
broadening of the concept of quality of service by involving
factors like environmental-friendliness, compliance to more
stringent standards – related to communication as well as
safety – and operational conditions, or even transparency to
the user.
In radio communication systems, energy may be wasted in the
following situations, some of which directional antennas can
help mitigate:
Idle listening − A node is turning on its radio to listen, but
there is no transmitter in the receiving range. Directional
antennas do not bring a solution to idle listening. In fact this
could even make the situation worse if there is no way to
change the beam orientation when the antenna is incorrectly
oriented (pointing to an area without nodes).
“Crying in the wilderness” − A node is sending when there
is no destination present. This cannot be solved by smart
antennas.
Overhearing − A node receives a radio signal but the content
is not addressed to it. In this case smart antennas will reduce
overhearing.
Collisions − Smart antennas could offer an improvement in
the case where collisions occur between traffic from pair-wise
communications; i.e. the traffic between A and B is in collision
with the traffic between C and D. With directive antennas, the
benefitt is due to improved spatial usage.
Range − To reach long range requires more energy than
short distance to transmit information with the same quality. In
this situation, adaptable directive antennas, in combination
with a suitable MAC protocol, can enhance performance by
concentrating the energy in the direction of the destination. As
such, for the same radio energy consumption, radio directional
antennas yield a longer range.
Potential applications that can benefit from using directional
antennas are (names are taken from the terminology defined
in the IST project e-SENSE):
• Wireless hospital
• Sub-network interconnection
• Store of the future
• Entertainment
In order to identify applications that would benefit from
directive antennas, the study considered the scenarios (see
Figure°1) elaborated within the e-SENSE project.
Figure 1: Application spaces, Use Cases, Applications and Scenarios
within e-SENSE
Each scenario has been analyzed with regards to the
applicability and potential benefits of using directional
antennas. The analysis highlighted for instance that scenarios
involving mobility during communication are difficult if not
impossible to benefit from directional antennas. However, the
use of directional and automatically reconfigurable (smart)
antennas would help in this regard.
The analysis has also shown that in applications where
directional antennas add benefits, the main benefits expected
are:
• Energy use improvement on both terminal and base
• Spatial reuse and system capacity improvement
• Extension of range
Another point linked to the use of directional antennas is the
need for dedicated or modified MAC (Medium Access Control)
protocols (i.e., for adaptation and control of directivity). The
study added a review of the state of the art and a classification
of MAC protocols using directional antennas. This work
classifies the typical MAC protocol algorithms with respect to
the constraints and specifics brought by directional antennas,
so that the most adequate algorithm can be chosen given the
application properties.
This work was partly funded by IST project e-SENSE. CSEM
thanks them for their support.
[1] Q. Xu, et al., “UWB Antenna with Improved Bandwidth and
Spatial Diversity using RF-MEMS Switches”, in this report,
page 80
83

A MAC Protocol for UWB-IR Wireless Sensor Networks
J. Rousselot, A. El-Hoiydi, J.-D. Decotignie
WideMac, a novel MAC protocol designed for wireless sensor networks using ultra wide band impulse radio transceivers, is compared with state of
the art low power protocols. It compares favourably with the best while offering additional services such as rapid discovery of neighbors and
positioning. These features are of high interest for distributed routing and for mobility enabled networks. Furthermore, contrary to the best known
protocols, it operates without requiring special modulation types.
Wireless sensor networks (WSN) are collections of small
electronic devices which communicate together wirelessly and
are equipped with one or more sensors, whose choice
depends on the application domain. They are often deployed
in environmental monitoring scenarios and must be able to run
on battery for months or years. The management of the radio
transceiver performed by the Medium Access Control protocol
has an important impact on power consumption.
Ultra Wide Band Impulse Radio (UWB-IR) is a communication
technique based on a time-domain approach. It offers
robustness to multipath propagation and to multi user
interference and allows accurate ranging. These properties,
associated with ultra low power consumption, make UWB-IR a
good candidate for WSN platforms.
Numerous low power Medium Access Control (MAC)
protocols for WSN have been proposed in the last few years.
All attempt to reduce four sources of energy waste: collisions,
overhearing, idle listening and overhead. Introducing an UWB-
IR physical layer has an impact on MAC protocol power
consumption and may even make some implementations
unusables. For example, the detection of an ongoing
transmission poses challenges with respect to implementation
with a UWB-IR radio. The best low-power MAC protocols
therefore require a modification of the UWB-IR modulation to
enable effective operation.
Figure 1: WideMac operation
WideMac is a novel MAC protocol designed specifically for
UWB-IR sensor networks. It operates as follows: each node
periodically transmits a beacon message announcing its
presence, and then listens for a brief period of time to detect
any incoming transmission. A node with a message to
transmit first listens until it receives the beacon of the
destination node, after which it can safely transmit the
message. The next time a message must be exchanged
between the two nodes, the time spent listening for the
beacon message can be greatly reduced because the
destination wake up time will be known. Figure 1 illustrates the
operation principle of WideMac.
WideMac power consumption was compared with state of the
art WSN MAC protocols (WiseMac and optimal preamble
sampling, SCP-Mac, Crankshaft) using mathematical models.
The results presented in Figure 2 show that WideMac was
able to match the performance of the best known protocols.
84
Remarkably, it is the only one to reach this efficiency without a
modification of the modulation scheme.
Figure 2: WideMac power consumption
WideMac also offers unique additional capabilities such as
rapid discovery of neighbours, ranging and positioning. This is
of special interest for distributed networks which require ad
hoc routing, and for mobility enabled networks such as large
scale environmental monitoring, herd control, vehicles
tracking, warehouse inventory or elderly care.

Optimum Operating Regimes for Wireless Sensor Networks
A. El-Hoiydi, J. Rousselot, J.-D. Decotignie
Wireless sensor networks are used in applications that have constraints in terms of metrics such as timeliness, lifetime and reliability. The WSN
designer needs to find a solution that meets the required objective metrics. Most of the time, applications have sets of objective metric values,
depending on the operating regime. This can be exploited to find a better solution to the needs by trading one objective value against another. This
study explores the potential of tuning in a combined manner the parameters of protocol stacks to achieve the best performance trade-off.
Although low power operation is often quoted as the main
quality of Wireless Sensor Networks (WSNs), such networks
may also need to satisfy other goals, depending on the
operating regime of the applications. For instance, a fire
detection application in a Mediterranean country may privilege
battery life in the winter when fires are unlikely. However,
when some humidity and temperature conditions are met, the
same application would place the priority on reactivity or
timeliness with respect to the propagation of the information.
This study shows the potential of tuning key protocol
parameters in order to achieve the best possible compromise
between operationally dependent and potentially divergent
performance metrics. The objective is to optimize the
operations of the WSN at run time.
In WSNs, three key performance metrics have been identified
[1] : timeliness which refers to the time to transport some
information from its source to its destination, reliability which
is the probability that a packet emanating from a source is
eventually received at its destination, and lifetime which is the
duration during which the network will operate continuously
Energy (J)
Latency (ms)
2.5
2
1.5
x 104
3
1
0.5
-10 -5 0
Tx Power
5 10
12
10
8
6
4
2
0
-10 -5 0
Tx Power
5 10
Figure 1: Total required energy and average latency with a varying
transmit power (CC2420 transceiver)
Emission power is one of the parameters that impact several
communication layers and may be tuned to look for the best
tradeoff between some of the metrics. It is controlled by the
physical layer, influences the link layer for instance by
changing the collision probability and impacts routing because
the number of direct neighbors and paths will change with the
power. Intuitively, the higher the power the higher the
consumption and the lower the latency (end-to-end delay).
The main question is whether there is a value of the
transmitted power that leads to a better trade-off between
consumption and latency. Power consumption and latency
have been evaluated by simulation (OMNET++) using a IEEE
802.15.4 radio (Chipcon CC2420), a contention MAC with
ideal wake-up scheme and routes generated by the Dijsktra
algorithm. The network has 120 nodes distributed over a field
of 300 x 300m. One of the nodes, the sink, collects messages
sent by all other nodes.
Figure 1 shows the total energy required to forward all
generated packets to the sink (upper graph) and the average
end-to-end latency experienced by those packets (lower
graph). Every different random position of the nodes results in
different blue curves. The red solid line curves represent the
average over all random positions. From the curves, it is clear
that with the CC2420 chip, there is no trade-off to make (at
least in low traffic situation) with the choice of the transmit
power. The maximum output power provides the best results
both in terms of consumed energy and in terms of latency.
The potential advantage of using multiple-hops to reduce the
consumed energy is not present with the CC2420 because of
its high base current consumption (8 mA in transmit mode and
18 mA in receive mode). If this radio had a base current
consumption of 2 mA both in receive and transmit mode, the
latency versus energy curve would be as illustrated in
Figure 2. In this case, latency and energy could be traded.
Latency (ms)
12
10
-10
8
-8
-9
-7
6
-6
-5
4
2
-4
-3
-2
-1
0
1
2
3 4
5
7
6
8910
0
4000 4500 5000 5500 6000 6500
Energy (J)
Figure 2: Latency versus Energy when varying the transmit power
(hypothetical transceiver)
An additional degree of optimisation in WSNs may be reached
by run-time tuning of certain protocol parameters in order to
tailor them to the application needs. CSEM has shown here
that there is potential tradeoff between reactivity and
consumption by tuning the transmitted power if the base
consumption can be reduced. Other parameters are under
investigation under the IST WASP project.
[1] IST-034963 WASP Project, Deliverable D4.2,
http://www.wasp-project.org/
85

Wireless Sensor Networks for Monitoring Cliffs in the Alps
A. El-Hoiydi, J.-D. Decotignie
In November 2006, CSEM in collaboration with CREALP and MAD technologies installed a wireless sensor network to monitor rock movements on
a cliff near Sion. Since then, it has been running without interruption and without battery change. This report describes the settings and the
intermediate results of this experiment.
Wireless sensor networks find natural application areas in the
domain of environmental sensing. In such networks, sensors
are connected to small battery powered nodes that include a
CPU and radio transceiver. The information sensed on the
node is transmitted to a sink node that is often connected to
some infrastructure (GSM, LAN, ...). CSEM, like many other
institutes, has deployed such applications for short-term
experiments. In this report, CSEM presents results of one of
the first long-term experiments without human intervention.
Figure 1: The Chandoline site with the sensor locations
The selected site is a cliff in the vicinity of the city of Sion in
the Swiss Alps. The cliff is under observation because
numerous rocks have fallen, jeopardizing an industrial zone
located at the bottom of the cliff (Figure 1). Monitoring is done
by measuring the relative movement of rocks using
extensometers.
Figure 2: An open sensor node with the extensometer
The site was originally equipped with extensometers wired to
a central monitoring station at the top of the cliff. For security
86
reasons, the existing monitoring installation was maintained
during the test phase. A new set of 3 extensometers has been
installed. Each accelerometer is connected to a wireless
sensor network node (Figure 2). Due to the propagation
conditions, an additional node is used as a relay between the
sensors and the sink node that collects all the measurements.
Each sensor node is built around the Xemics XE88LC05
processor and a radio module based on the XE1203
transceiver operating in the 868 MHz band. The protocol stack
includes Wisemac, a simple dynamically built routing protocol
and clock synchronisation. Wisemac is an ultra low power
contention medium access control based on an adaptive
preamble sampling technique [1] developed at CSEM under the
WisenetTM project. Nodes and sensors are powered by a
single 20 A.h Li Battery.
Every minute each sensor node transmits the reading of the
extensometer and the local temperature (used for
compensation) to the sink node (Figure 3). Battery voltage
and other statistics are also sent regularly. Figure 1 shows the
routes (from the nodes to the sink) that were found best by the
routing algorithm.
Position [mm]
Temperature
Figure 3: Plot of the sensor measurements over a week
The system has been running without human intervention for
more than a year. Measurements match those captured by the
pre-existing installation. This shows that such a system offers
a viable solution. Compared to wired systems, it is easier to
install and does not suffer from potential damage to the wires.
The predicted battery life is around 10 years for the sensor
nodes but less for the relay and the sink node. Long term
campaigns in isolated locations are possible.
[1] A. El-Hoiydi, et al., “WiseMAC: An Ultra Low Power MAC
Protocol for Multi-hop Wireless Sensor Networks”,
ALGOSENSORS 2004, 18-31

Control Electronics for Bio-Sensing Textiles to Support Health Management
B. Gros, J. Luprano, J.-A. Porchet, R. Rusconi, A. De Sousa, A. Ridolfi, J. Solà I Caros
A versatile portable data acquisition device has been designed in the frame of the BIOTEX project in order to acquire and process the data of
innovative sensors integrated in textile for the measurement of several parameters in sweat and blood.
The European research project BIOTEX [1] is aimed at the
development of biochemical-sensing techniques for health
monitoring, compatible with the integration into textiles. For
that purpose several sensing textile patches have been
developed by the project consortium in order to monitor
physiological parameters in body fluids such as sweat and
blood. To evaluate the correct operation of such sensors,
three main applications have been selected: (1) metabolic
disorders in diabetes, (2) obese children and sports, and (3)
sore monitoring/wound healing (Table 1).
Applications Sensing method In sweat In
blood/plasma
Sports Optical
spectroscopy
SpO2
Wound Optical
pH
immunosensor
CRP
Sports Optical
colorimetry
pH
Sports
Diabetes
Wound
Impedance Conductivity
Sports
Diabetes
Capacitance Sweat rate
Sports Electrochemical Electrolytes
concentration
Table 1: Sensing methods referenced to targeted applications
One of the main tasks of CSEM in the project was the
development of a lightweight portable control electronics
(Figure 1) able to acquire and process all sensor signals for
the different BIOTEX applications.
Figure 1: Portable control unit
The digital section of the portable control unit is built around a
power-efficient ARM7 microprocessor. A removable miniature
memory card (SDcard) stores up to 2 GBytes of data that can
be downloaded to a PC by using a standard USB card reader.
An integrated Bluetooth module provides the feature of realtime
data streaming. The user interface of the portable control
unit has been designed in order to allow the usage of the
monitoring system by non-technical people. In this sense a
high resolution color LCD is used and together with its layer
sensitive to the pressure of the fingers (touch screen) allows
the user to press the virtual buttons displayed on the screen to
navigate through the menus.
The control unit can be customized to a specific application by
changing a dedicated sensor board. This makes the unit
highly configurable and reusable as a versatile mobile
platform for other applications with other sensor data.
The unit provides an optical connector for the SpO2 sensor,
also developed at CSEM. The SpO2 sensor uses an
innovative approach for the photoplethysmographic
measurement at the thorax by using a set of plastic optical
fibers to capture the light and the signal of which is transmitted
to the remote light sensor, integrated in the control unit. These
fibers are woven using conventional textile techniques
(Figure 2) and can thus be integrated into garments.
Figure 2: Woven optical fibers used for the SpO2 sensor
The bio-sensors developed during the first two years of the
project have been integrated into wearable elements and will
be tested on volunteers during the last phase of the project.
The BIOTEX project partners are CEA-LETI, Thuasne and
Sofileta in France, Smartex, Penelope and University of Pisa
in Italy and Dublin City University in Ireland.
This work is partly funded by the European Commission.
CSEM thanks them for their support and the project partners
for their collaboration.
[1] BIOTEX stands for “Bio-sensing Textile for Health Management”
(http://www.biotex-eu.com)
87

Wearable Systems to Protect Rescuers and Firefighters during Operations
J. Luprano, G. Voirin, G. Dudnik
After the first 22 months of activities, the European project ProeTEX [1] confirms the feasibility of an integrated and wearable system for Firefighters,
Civil Protection Rescuers and Victims, that will improve safety by monitoring vital signs and environmental signals. The implemented prototypes are
being submitted to field trials and the results will provide valuable feedback that will contribute to the future design.
In the frame of the European Project PROETEX [1] , CSEM in
collaboration with 22 partners is developing smart garments
with wearable electronics and sensors for helping rescuers
during operations. The project aims to improve the security
and efficiency of rescuers by integrating portable sensors and
communication systems into the garments. The continuous
verification of vital and environmental signs allows the
prediction of extreme situations regarding the health status
and safety of people during their interventions thus becoming
a valuable tool in the diagnosis of the risks and eventually
saving their lives.
The main tasks of CSEM are the design of new biosensors [2] ,
the definition of a network topology for the textile and nontextile
sensors and the conception of low power portable
electronic devices. The portable devices integrate the
heterogeneous electronic subsystems that collect, synthesize,
and transmit the vital data and information to a remote station
in a reliable way.
This first version of the prototype collects the information of
the different sensors that are distributed in a T-shirt in contact
with the body (inner garment) by connecting the analog
signals to a portable module located in the outer garment.
Information from sensors located in the outer garment are
treated locally and transmitted along the jacket (outer
garment) by the implemented wired network to the portable
module. The latter collects, processes, and synthesizes the
information. This module is able to transmit wirelessly point-topoint
at a maximal distance of 30 meters to a computer using
a standard protocol. The application software allows the
processing of the data online, and stores it for further analysis
or historical record. The following sensors are currently
integrated:
• Vital body signs: heart and breathing rate, skin
temperature, motion and activity.
• Environment data: external temperature, GPS-based
location.
Figure 1: Main blocks of the first system prototype
The first prototypes, whose system overview is shown in
Figure 1, have proven that the project goals are reachable,
without dramatic modification of the end user intervention
routine. The first trials were carried out by the Italian Civil
Protection (ICP) and the “Brigade des sapeurs-pompiers de
88
Paris (BSSP)” under the lead of the partners in charge of this
activity, EUCentre and Smartex. The equipment was tested by
the firefighters in two typical situations:
• Obstacle trail reproducing routine (and demanding)
gestures of firefighters during their interventions
• Fire control in training chamber (Figure 2)
Figure 2: BSSP firefighter wearing ProeTEX garment during field
trials in St. Denis (Paris – 12 December 2007)
The next generation of prototypes will be personalized for
each type of application and will add the following features:
• Local treatment of the vital signs for further integration to
the sensor network (e.g. combination of heart and
respiration signals) and addition of oximetry and sweat
measurements.
• Integration of environmental information: e.g. heat flux and
toxic gases.
• Implementation of a Body Area Network (BAN) to link toxic
gas sensors located inside the boots.
• Addition of mid and long range communication with
networking capability.
• Provision of local alarms suitable to harsh environment.
CSEM thanks the European Commission for their support and
the project partners for their collaboration.
[1] http://www.proetex.org
[2] http://www.biotex-eu.com

MEMS Based Miniature Catheter Probe for Ultrasound Imaging
R. Gentsch, J. Luprano, P. Pilloud
A miniature capacitive micro-machined ultrasound transducer (CMUT) has been developed in the frame of an EURIMUS project. The first target
application is a 3mm diameter catheter probe for intra-cardiac imaging. A dedicated 64-channel low noise preamplifier was designed by CSEM to
compensate the lower sensitivity and achieve optimum imaging performance.
MEMS technology opens exciting perspectives for medical
ultrasound imaging transducers: compared with traditional
piezoelectric transducers (PZT). The silicon MEMS approach
offers potentially lower fabrication costs for volume production,
better reproducibility, improved acoustic radiation pattern and
wider frequency response.
VERMON SA, a French SME company with more than 20
years of experience in development and manufacturing of high
performance ultrasonic devices for medical and industrial
applications, initiated an EURIMUS project called MEMSORS
(Micromachined Electrostatic Membranes for acoustic
SensORS). The goal of the project is to develop a miniature 3
mm diameter catheter probe for intra-cardiac imaging with 64
elements. Such a small probe already exists in the lineup of
VERMON, but based on PZT technology and thus quite
expensive to manufacture. The price of such probes is a
sensitive factor since they are single use devices. However,
the availability of low-cost CMUT probes would encourage
surgeons to use them more often to help them during critical
heart operations.
The project consortium was formed by partners from France,
Germany and Switzerland providing excellent
complementarities: VERMON (Tours, France), as project
initiator and coordinator, was involved in all project phases,
from specification, design and simulations to the integration
and evaluation of the prototypes. STMicroelectronics (Tours,
France) and MicroFAB (Bremen, Germany) were the two
MEMS foundries processing the CMUT wafers which allowed
two different processes to be tried out. The University of Tours
was involved with two of its laboratories, the “Laboratoire
Ultrasons Signaux Instrumentation” (LUSSI) and the
“Laboratoire de Microélectronique de Puissance” (LMP), both
in the design phase and later in the detailed characterization
of the CMUT samples. Hybrid SA (Chez-le-Bart, Switzerland)
was in charge of the interconnection and packaging issues.
The major challenge was to mount a 64-element CMUT
measuring 2 mm by 14 mm on a dedicated substrate by
providing a connection to four miniature 18-wire ribbon cables
on the opposite side. Due to the limited size of the probe all
had to fit into a 3 mm diameter catheter.
Figure 1: 64-element CMUT (2 x 14mm 2 ) on interconnect flex carrier
CSEM’s task was to design a 64-channel preamplifier module
able to compensate the lower CMUT sensitivity compared to
PZT probes by providing a 20 dB gain over a 30 MHz
bandwidth. Very low noise level was one of the key
specifications, in order to keep the low level echo signals
(sub-millivolt level) as clean as possible. The most demanding
requirement was to keep the preamplifier “transparent” for the
ultrasound imaging equipment normally operating with PZT
probes. In other words the high voltage pulses sent to the
probe for the acoustic emission, presenting amplitudes up to
200 V and rise time in the order of 10 ns, had to pass the
amplifier in the opposite direction (from output to input) without
damaging the sensitive preamplifier circuit. The overload
recovery time had to be kept very short (< 1 μs) in order to
minimize the distance to the first visible echo. Another
particularity of CMUT devices is that they need a DC voltage
biasing (up to 200 V) to get optimum acoustic characteristics,
similar to electrostatic microphones.
Figure 2: 64--channel preamplifier module and catheter probe (left
lower corner: probe tip detail in special transparent finish)
During this 3-year project all “building blocks” could be
validated: MEMS processing (CMUT design, processing
parameters, membrane stress and coating for optimal
acoustic performance, through-wafer vias), probe assembly
and interconnection of the 64-element transducer to the
cables and electronic module performance. The successful
integration of these “building blocks” prepares the way to an
industrial product and the imaging tests done with a final
version of the CMUT transducers indeed showed increased
acoustic performance over PZT transducers.
CSEM thanks the OFFT / CTI for their financial support for the
work done by CSEM, the EURIMUS Office for their support to
the overall project and all the project partners for their
valuable contributions. Pictures: courtesy of Hybrid SA and
VERMON SA.
89

.
90

MICROROBOTICS
Christian Bosshard, Philippe Steiert
Figure 1: Roadmap Microrobotics
The research in Microrobotics at CSEM is based on three
Technology Platforms (see Figure 1). A new platform on
sensor integration will be started in 2008.
Development of fast and precise desk-top industrial
robots for microcomponent assembly
In March 2007 the CSEM Robotics team won the first prize of
the Swiss Technology Award with the concept of the Micro
Factory for assembly processes. Based on the PocketDelta
the concept was shown as a live demonstration at the
Hannover Fair 2007 where it was nominated for the Top Five
of the prestigious Hermes Award for excellent technical
innovations.
In order to extend the technology platform for the
MicroFactory to a wider scope of Assembly, the research
activities are focused on the three topics (i) modular software
tools of object oriented robotics (ii) generic image processing
for automation, and (iii) process-driven robotics control. In
2007, the existing platforms were supplemented and the
software framework and the control electronics were adapted
to current industrial needs.
A large part of the research activities were carried out within
two EU projects. In the project Hydromel a process for the
automatic recognition of the position and orientation of
unordered parts has been developed. In the project Nanohand
algorithms have been developed for the control of a cameraguided
mini robot to handle carbon nanotubes.
Handling of fluids and of cells in fluids by combining
microfluidics & robotics
The Microfluidics & Microhandling team has developed novel
methods for the handling of samples and reagents in life
sciences. This is achieved through a combination of
microfluidics and robotics that allows the sorting and
concentration of small particles (cells, functionalized
microbeads). A further topic is the fabrication of completely
packaged microfluidic systems.
Within these activities the integration of sensors and actuators
in microfluidic systems played an increasingly important role
throughout last year. The infrastructure for the fabrication of
prototypes was extended through a micromilling machine, a
thermal bonding machine and a lamination apparatus. In
addition, the combination or precision robotics and
microfluidics has led to the development of a system that
allows the automatic selection, immobilization and collection
of cells for microinjection.
Packaging and interconnect technologies
The Optics & Packaging team has developed customerspecific
integration solutions from the design phase to the
assembly for products in the field of optoelectronics, sensing,
MEMS systems and microelectronics. A special focus was put
on the development of bonding processes (adhesive fixing,
soldering).
The packaging activities at CSEM were further extended and
Alpnach could establish itself as the center for this domain
within CSEM. In terms of technology the existing flip-chip
bonding processes were extended. This now allows the
simultaneous application of electrical contacts to smart Silicon
sensors and leak-tight sealing with respect to liquid and
gases. Typical applications are in the area of biodiagnostics
with liquids and the hermetic sealing of MEMS devices.
Integration of disciplines and industrial relevance
The strength of CSEM Microrobotics research program
continues to be the integration of the various disciplines
including robotics, embedded systems, SW engineering,
microfluidics, optics, sensing as well as microsystems
integration and packaging.
A representative example is the development of a highly
compact laser scanner for dermatologic applications carried
out for the industrial client Pantec Biosolutions AG which also
led to the nomination of the Medtech Award 2007. The
successful implementation required the following
competences: actuator driver engineering (robotics), digital
signal processing and algorithms, mechanics with micrometer
precision, optics, sensing, electronics.
Research partners
CSEM research partners in the field of Microrobotics are
ETHZ (Eidgenössische Technische Hochschule Zürich), EPFL
(Ecole Polytechnique Fédérale de Lausanne), IMT (Institut de
Microtechnique, Université de Neuchâtel), HSLU (Hochschule
Luzern), and BFH-TI (Berner Fachhochschule Technik und
Informatik, Biel)
Research at CSEM Microrobotics Division in Alpnach is
supported by the Cantons of Central Switzerland through the
Micro Center Central Switzerland (MCCS).
91

NanoHand – A System for Automated Nano-Handling – An Integrated EU Project
A. Steinecker
In the integrated EU-project NanoHand of FP6 a nano-manipulation platform will be developed that carries out automated nano-handling of
nanotubes or nanowires. Individual handling of nano-components will be addressed inside or outside of a scanning electron microscope (SEM). It is
targeted to build prototypes for design and testing of future nano-devices. Together with project partners CSEM realizes a system for nano-handling
under a light microscope
Nanotubes and -wires show interesting electrical, chemical
and mechanical properties. Different application domains
benefit from the use of nanowires, as for the following two
examples: (i) Nanotubes attached to scanning tips can
improve their resolution or add chemical probing sensitivity. (ii)
Nanotubes integrated into novel nanoelectronic devices could
improve heat dissipation or act as elements in transistors.
Handling and positioning of the nanotubes is feasible by
complementary approaches: parallel catalytic growth on predefined
positions or individual handling by single pick-andplace
operations. The latter is focus of the presented work.
Individual handling is essential for building prototypes of nanodevices,to
achieve a high degree of flexibility and to enable
quality control of devices. Nevertheless the task is
complicated and lacks dedicated instruments.
NanoHand is an integrated European project run under the 6th Framework Programme [1] . It started in June 2006 and will end
in May 2009. Its goal is to provide exploitable systems for
nanohandling.
The project is grouped into the following sub-projects
• SP 1: Nano-manipulators and technologies (led by CSEM)
• SP 2: Applications and industrialization (led by ST)
• SP 3 and 4: Accompanying measures and management
CSEM is leading SP 1: the development and integration of
sub-systems for nano-handling. A close collaboration with
leading scientific and industrial partners from Europe has
been established. The sub-systems for nano-manipulation
consist of mobile and fixed piezo robots for precise locomotion
and flexible reconfiguration (EPFL), gripping and handling
strategies for reliable manipulation of nanotubes and –wires
(MIC), and vision and control for stable object detection and
task automation (OFFIS, CSEM). These components are
integrated into a set-up that can be operated in an SEM or
under a light microscope.
CSEM is developing a microscopic set-up for the automated
handling of nanowires outside of the SEM (Figure 1).
Nanowires are structures with lateral dimension of up to
several 100 µm that can already be observed using light
optics. The set-up consists of several piezo robots (cartesian
x-y-z stage, mobile robots that can move and rotate on a
surface, rotating stage) developed by EPFL. They carry
microgrippers provided by MIC to manipulate nanowires.
CSEM has integrated the various components under a light
microscope (Figure 2). A modular control system has been
developed that will enable automated handling based on
visual servoing of the robots. In the upcoming project phase
the hard- and software elements will be adapted for
92
integration into an SEM and enable automated In-SEM
nanohandling.
10 µm
Figure 1: Silicon nanowires (diameter approx. 200 nm) under optical
microscope (see Figure 1)
Overview
camera
Mobile
Figure 2: Nanomanipulation system under a light microscope
integrated at CSEM. Sub-systems have been provided by EPFL
(mobile nano-robot and rotating stage) and MIC (gripper and
samples, not visible in the picture).
Project partners: CSEM, EPFL, EMPA, Eurexcel (GB),
Futuretech (DE), Klocke Nanotechnik (DE), Technical
University Denmark - MIC (DK), Nascatec (DE), OFFIS (DE,
Coordinator), ST Microelectronics (IT), VDI VDE-IT (DE).The
project is funded by the European Commission in the 6 th
Framework Programme (FP6-2005-IST-5, contract number
034274) and by the MCCS. Their support is gratefully
acknowledged.
Figure 3: Official NanoHand logo
Microscope
objective
Rotation stage
xyz stage
[1] S. Fatikow, V. Eichhorn, A. Sill, A. Steinecker, C. Meyer,
L. Occhipinti, S. Fahlbusch, I. Utke, P. Bøggild, J.-M. Breguet,
R. Kaufmann, M. Zadrazil, W. Barth, "NanoHand: micro-nano
system for automatic handling of nano-objects", International
Symposium on Optomechatronic Technologies (ISOT 2007),
Lausanne, Switzerland, 8-10 October 2007

Microfactory – A Flexible Assembly Platform
P. Glocker, R. Wyss, P. Schmid, U. Zbinden, J. Taprogge, M. Honegger, A. Steinecker, G. Gruener, C. Meyer
In the future, small components will be assembled on small machines. CSEM has designed small-sized Delta robots with integrated controller
hardware and minimized external cabling and footprint. The PocketDelta is an ideal, modular, micro-assembly platform for automatic production in
desktop applications. A demonstration Microfactory with four robots shows great potential for saving resources in miniaturized production systems.
In the past few years CSEM has invested in the
miniaturization of robot systems based on parallel Delta
kinematics. The result is the PocketDelta [1] , a highly
integrated robot platform for micro-assembly applications with
up to 4 degrees of freedom (Figure 1). This new tool shows a
high potential for future assembly technologies due to the
following specifications:
• High precision: Repeatability < 5 µm
• Short cycle time: up to 3 cycles per second
• Small size: 120 x 120 x 240 mm
Figure 1: The PocketDelta robot
In March 2007, CSEM was bestowed with the First Prize of
the prestigious Swiss Technology Award [2] for the concept of
a miniaturized modular assembly line (Figures 2 and 3).
Figure 2: CSEM receives the First Prize of the Swiss Technology
Award 2007 for its Microfactory concept
At the Hanover Fair 2007, CSEM presented a miniature
assembly line with four PocketDelta robots (Figures 4 and 5),
demonstrating assembly of micro-planetary gears with a
housing diameter of 6 mm. CSEM landed within the top-five
finalists of the Hanover-Fair–associated Hermes Award [3] .
Figure 3: Microfactory concept for a desktop assembly line with 5
PocketDelta robots
Figure 4: Microfactory assembly line with 4 PocketDeltas presented
at the Hannover Fair 2007
The high position accuracy of the PocketDelta and its short
cycle times bring new economical advantages. Note that the
MicroFactory does not solve existing assembly problems.
Rather, a new technology platform has been launched for
future low-cost production systems. Products to be
manufactured by this platform should be designed with its
performance in mind. One great advantage, though, is the fact
that the same system can be used during prototyping and
production, reducing development time and risk.
Figure 5: Close-up look of the Microfactory assembly line
CSEM is developing additional components for the Microfactory,
such as part feeders and integrated sensors for force
measurement and automatic part location, which will improve
the performance of the Microfactory assembly line.
[1] S. Perroud, et al., “New pocket and desktop Delta robots with
integrated controllers”, CSEM Scientific and Technical Report
2006, page 80
[2] http://www.swisstechnology-award.ch
[3] http://www.hannovermesse.de/hermesaward_e
93

Isolation and Reversible Immobilization of Single Cells
S. F. Graf, P. Schmid, H. F. Knapp
An innovative system to meet the need of drug researchers is under development. The novel approach integrates new technologies including
microrobotics and microfluidics to achieve a high throughput screening rate which will replace time consuming and costly manual operations used
today. To this end, a multipurpose robotic system called ‘CellBot’ was developed consisting of the high-precision robot ‘µDelta’, the fully automated
inverse reflected light microscope ‘iMic’, the tool stage, the fixed working platform and the “Carousel” for reversible immobilizing of the cells. By
using this visual feedback controlled setup an automated isolation and reversible immobilization of single Xenopus laevis oocytes could be
demonstrated.
Cell-based assays are set to become the preferred choice of
screening in drug discovery research, potentially overtaking
more traditional approaches that include animal models. New
target screening often requires the use of cell assays to detect
specific cellular pathways of chemical compounds, therapeutic
proteins, siRNA agents and other structures of interest. Insight
from these assays could help more efficient discovery of
effective drugs, thus saving time and costs as well as the
need for future secondary screens. The emphasis now for
cell-based assay manufacturers is to develop easy-to-use and
highly sensitive cell systems as an alternative to current
rodent bioassays. High throughput screening (HTS) using cellbased
assays will particularly become increasingly needed for
both industrial and scientific applications. Introduction of DNA,
siRNA, or other substances into cells is one important
micromanipulation technology applied to develop and optimize
various cellular systems, which enables cell systems either to
more closely approximate in vivo testing or to become more
competent or more specific for various in vitro applications.
However, the pharmaceutical industry needs a highthroughput,
efficient, and automated system for direct delivery
of substances (including compounds, DNA, siRNA and mAbs)
into a large number of cells for HTS use.
To address this need, the development of an automated
microinjection system is in process. Microinjection is a
technique where a glass capillary filled with substances is
controlled by a micromanipulator. Cells have to be individually
immobilized while the capillary with an apex of 0.5 to 10 µm
diameter penetrates the cell and a pressuring device injects
the substances.
Therefore, as a first step, the isolation of single Xenopus
laevis oocytes with a following reversible immobilization is
demonstrated. The “CellBot” [1] setup is used, consisting of a
high precision robot “µDelta” equipped with a glass capillary
connected to a peristaltic pump, a fully automated inverted
light microscope “iMic” and a fixed working platform with a
Petri dish and a “Carousel” for further cell manipulations
(Figure 1). To start the process, the user has to place a
suspension of Xenopus laevis oocytes into a Petri dish. Via
the user interface the routine can be started: The iMic scans
the Petri dish (Figure 2) and cells of interest are automatically
identified via a pattern matching software based on a set of
given parameters If a cell is detected, the glass capillary is
automatically guided by vision feedback to pick up the cell and
places it into the carousel. The carousel contains specially
designed cone structures for immobilizing the cells, with or
without negative pressure. By rotating the “carousel” the cell is
moved to the microinjection position, which will be
implemented at a later stage. Finally the carousel can be
94
rotated to two additional positions, where the cells can be
released into a collection or waste container, respectively. The
release of the cells is aided by pressure pulses. The collection
container can be removed by the user for further processing.
collectio
n
carousel
pipette
petri
Figure 1: Workspace of the CellBot where the micropipette is about
to pick a cell to transfer it to the carousel for immobilization.
Figure 2: A special combination of bright– and darkfield illumination
enables simultaneous detection of several parameters of the
Xenopus laevis oocytes, such as shape, size, and coloration, that will
identify viable cells.
This work was partly funded by the EU (project NMP2-CT-
2006-026622) and the cantons of central Switzerland and the
MCCS (Micro Center Central Switzerland). CSEM thanks
them for their support.
[1] T. Stöckli, et al., “High precision robotics for automated cell
handling“, CSEM Scientific and Technical Report 2006, page 83

Bonding of Glass or Silicon Chips with a Self-Sealing Photostructurable Elastomer
J. Auerswald, F. Cardot, P. Niedermann, A. Ibzazene, M. Fretz, N. Schmid, H. F. Knapp
When it comes to the integration of planar electrodes on glass, quartz, silicon or thermoplastic chips into microfluidic systems, standard bonding
methods like diffusion bonding, anodic bonding, thermo-compression bonding etc. do not work. Surfaces carrying electrodes cannot be sealed with
a stiff material. The challenge is even bigger when two glass chips with facing electrodes and microfluidic channels in between are required by the
application, with an alignment precision down to a few micrometers. Photostructurable polysiloxane could be a solution.
The use of photostructurable polysiloxane combines two
advantages: Firstly, the good alignment precision of
microfluidic channels made by photolithography. Secondly,
the reliable permanent bond of silicones to glass, even if the
glass chips carry electrodes. Photostructurable polysiloxane is
a material known from ISFET and ChemFET sensor
packaging. There, typical lateral structure dimensions are
several millimeters, sometimes slightly below 1 mm, and are
shaped as simple O-rings [1, 2] . However, the use of this
material class for microfluidic systems with microfluidic
channel networks containing junctions or intersections at
channel widths well below 1 mm, and electrodes in the
channels has not been demonstrated yet. One of the critical
issues is the precise bonding of the cured material to the glass
counter chip which also has electrodes on its surface.
Figure 1: LEFT: Bonded glass chips with facing top and bottom
planar electrodes, alignment marks and fluidic access holes. The
microfluidic channels are photo-structured into the elastomeric
intermediate layer. RIGHT: Bonded chip filled with a colored fluid.
25 μm high microfluidic channels with a width down to 200 μm
(and less), with channel junctions, into photostructured
polysiloxane on a glass substrate with planar electrodes were
structured. It was further achieved to permanently bond the
cured material to counter glass chips with planar electrodes.
The whole microfluidic system was leak tight, even without an
external clamp (Figure 1). The elastomer-based
photolithography and the precise bonding process allow for
alignment accuracies down to a few micrometers.
This high precision combined with good sealing provides a
viable alternative to the until now rather unsatisfying sealing
results obtained with classic negative tone photoresists such
as SU-8, BCB, or polyimide.
A possible application is shown in Figure 2. First,
microelectrodes are fabricated on a bottom glass wafer. Then,
in a second mask process, the photostructurable polysiloxane
is deposited and structured. Before dicing, the bottom wafer is
protected by a removable resist layer. After removal of the
protective resist and surface activation, the chips can be
bonded to the diced chips of the top wafer. The top glass
chips also have electrodes and pre-drilled fluidic access holes.
The bond is permanent, due to the applied surface activation.
Fluidic connectors can be glued or tape-bonded above the
fluidic access holes.
Figure 2: CAD explosion model (left) and global view of the bonded
chip with facing planar top and bottom electrodes, and Luer
connectors (right).
The alignment precision depends on the used bonding
machine and can be as good as 1-2 micrometers with a
device bonder. The chips sealed well over the entire gage
pressure range up to 28’000 Pa (4 psi), even after the 10th
pressure cycle (Figure 3). This is more than enough for typical
microfluidic applications.
Figure 3: Example of a sealing test. The chips seal well at pump
gage pressures of 30’000 Pa (4 psi), even after the 10 th pressure
cycle. This is more than good enough for typical microfluidic
applications.
Potential applications include high-end niche markets for labon-chip
systems designed for dielectrophoresis, dielectric
spectroscopy, low voltage AC-EOF pumping and other
microfluidic applications requiring photolithographic
electrodes.
This work was partly funded by the EU (project IST-FP6-
027540, IntegramPLUS). CSEM thanks them for their support.
[1] P. Temple-Boyer, J. Launay, I. Humenyuk, T. Do Conto,
A. Martinez, C. Beriet, A. Grisel, Microelectronics Reliability 44
(2004) 443-447.
[2] P. Arquint, M. Koudelka-Hep, B.H. van der Schoot, P. van der
Val, N. F. de Rooij, Clin. Chem. 40/9 (1994) 1805-1809.
95

Sensor and Connector Integration into Microfluidic Systems using Biocompatible Tape
Gaskets
J. Auerswald, H. Haquette • , H. Keppner • , J. Nestler •• , S. Bigot ••• , M.-C. Beckers ∗ , J. Gavillet ∗∗ , G. Delapierre ∗∗ , N. Schmid,
S. Berchtold, E. Portuondo-Campa, S. Graf, H. F. Knapp
The project goal is to develop a thermoplastic microfluidic cartridge with an integrated glass-based surface plasmon resonance (SPR) sensor for
label-free protein detection. Laser-cut tapes were used for sensor and connector integration. First prototypes were fabricated and tested in a protein
demonstration assay. The non-specific binding behavior of the tapes with respect to antigen, antibodies, proteins, DNA and RNA was investigated.
Laser-cut tape gaskets allow the integration of glass or silicon
based sensors into low cost thermoplastic microfluidic
systems [1] . The advantages of this bonding approach are:
• High degree of design flexibility (multi-channel layouts).
• Good bonding to polar (glass, quartz, silicon, ceramics)
and non-polar (thermoplastics) surfaces.
• Presence of bio-molecules on the sensor surface is
possible during the bonding process (no heat, UV or
plasma required).
Tape bonding also allows the integration of fluidic connectors
on the chip and the sealing of channels with cover tape.
Figure 1 shows an assembled prototype and laser-cut tapes.
Figure 1: Left: Prototype with glass-based SPR sensor chip, injection
molded thermoplastic COC microfluidic channels, and fluidic srew
connectors. Right: Laser-cut tapes were used for sensor chip
bonding (bottom tapes), channel sealing (top tapes), and connector
bonding.
The prototypes have successfully been tested in protein
demonstration assays. In these assays, human pain markers
were detected in specific binding assays on glass chips. The
glass chips, already carrying the probe molecules, were tapebonded
to thermoplastic COC injection molded microfluidic
channels.
Further, a gel actuator was successfully tested as an
alternative to the external pump, used today. This gel
actuator, together with sample, buffer and reference
reservoirs, will be integrated into the cartridge in the future.
Figure 2: PE-CVD coating of the channel substrates. All channels
were coated hydrophilically, except at the junction area, where a
hydrophobic flow stop was desired. The coated chip was sealed with
an uncoated laser-cut cover tape.
For controlled actuation and flow behavior with the integrated
gel actuators, the cartridge will also possess hydrophobic flow
stops at the inlet channel junction area. For this purpose, the
COC cartridge will be treated with PE-CVD coatings to define
hydrophilic and hydrophobic channel sections. The wetting
96
angle for aqueous solutions is defined by the prevailing polar
or non-polar bond character in the coating. First tests
demonstrated the feasibility of the flow stops (Figure 2).
For sensitive protein assays, it is important that the proteins
are delivered to the sensor and not lost due to non-specific
binding at the microfluidic channel walls. The bonding tapes,
the cover tapes, the COC and the PE-CVD coatings were
tested for non-specific binding of antigens, proteins from
serum, biopsy and cell lysate, and antibodies. In addition, the
tapes were also tested for non-specific binding of DNA and
RNA. Tapes, COC and PE-CVD coatings showed relatively
low non-specific binding in these tests (Figure 3).
Figure 3: Example of a non-specific binding test with antigen and
proteins from serum, biopsy and cell lysate. Compared to reference
glass and COC slides, the fluorescence signal indicates low nonspecific
binding of bio-molecules on a number of tested tapes.
The work was supported by the EU (IST-FP6-016768). SPR
chips were provided by Zeptosens (a division of Bayer AG).
•
HE-ARC, La Chaux-de-Fonds, Switzerland
••
Technische Universität Chemnitz, Germany
•••
Cardiff University, UK
∗
Eurogentec SA, Belgium
∗∗
CEA Grenoble, France
[1] J. Auerswald, et al., Bonding of SPR Sensors on Glass Chips to
Thermoplastic Microfluidic Scaffolds, Proc. Smart Systems
Integration Conference, Paris, March 27-28, 2007, 153-160.

Pressure Sensing Strip for Rapid Aerodynamic Testing
N. Schmid, M. Fretz, S. Bitterli, T. Burch, L. Neumann, J. Auerswald, H. F. Knapp, S. Graf, C. Bosshard, P. Sollberger • ,
F. Zimmermann • , Z. Stössel • , T. Harvey •• , J. Zhu •• , R. Hamza ∗
A pressure sensing strip is being developed in order to measure pressure profiles for rapid aerodynamic testing. It combines state of the art
pressure sensing technology with integrated micro-fluidic pressure signal guidance in order to produce a non-intrusive pressure distribution
measurement device. A patent is pending.
Currently low pressure profiles are primarily measured with
pressure transducer arrays: A number of tubes lead from a
pressure transducer array to corresponding measuring taps
on the surface to be measured [1] (Figure 1). Setting up such a
system is time consuming and costly and on thin profiles or
brittle materials it is not even an option (e.g. sails, glass).
Alternatively, non intrusive pressure sensitive paints can be
utilized, but there is a lack as far as sensitivity, accuracy and
reproducibility is concerned.
Figure 1: Comparison between conventional and CSEM PS strip
The pressure sensing strip measures pressure profiles nonintrusively
without impeding sensitivity. The device can directly
and easily be placed onto the surface to be measured (Figure
2). It combines state of the art pressure sensing technology
(piezo-resistive sensors) with integrated microfluidic pressure
signal guidance (Figure 3). A film with integrated microchannels
guides pressure signals from an arbitrary point on
the surface to the sensor, which does does not obstruct the
fluid flow at the place of measurement..
Tape with integrated
micro-channels
Figure 2: Pressure sensing strip
Pressure
sensors
Electrical
connection
Courtesy of BMW-
Pressure sensor
Integrated micro-channel
Figure 3: Pressure sensor on flexible PCB manufactured at Epigem
Wire-less data transmission can be utilized in order to further
increase system flexibility such as mounting the entire device
on a rotating blade (e.g. wind turbine).
Potential markets can particularly be found in R&D testing
environments (e.g. wind tunnels) in following industries:
• Automotive
• Aerospace
• Wind turbines
• Urban goods
• Watercrafts
• HVAC
Table 1: Targeted specs
Pressure range 6000 Pa
Pressure accuracy 30 Pa
Pressure resolution 3 Pa
Strip thickness (at measuring points) < 0.8 mm
Strip length 20 to 500 mm
Temperature range 0 to 60 °C
Measuring speed per sensor 300 Hz
This work was supported by the EU, (project IST-FP6-027540,
IntegramPLUS) and the MCCS Micro Center Central
Switzerland. CSEM thanks them for their support.
•
Hochschule Luzern Technik & Architektur, Horw
••
Epigem Ltd, Redcar
∗
Yole Développement, Lyon
[1] Race Car Aerodynamics, Joseph Katz
97

Pressure Sensing Strip – Packaging Aspects
M. Fretz, N. Schmid, T. Harvey • , J. Zhu • , A-C. Pliska, C. Bosshard
A face-up bonding process for MEMS devices on flexible prints based on silicone rubber was developed. The electrical contacts were provided by
gold wire bonds. The process allows the fabrication of flexible pressure sensing strips specially suited for non destructive measurements in R&D
environments like wind tunnels.
Flexible prints are widely used in (micro-) electronics
applications. High resistivity to temperature makes them as
easy to handle as rigid FR4 boards. In order to extend the
applications of flex prints to microfluidics, it is necessary to
develop adequate bonding processes: MEMS devices need to
be mounted on flexible platforms. In this case, the flexible
platform exhibits air channels with two openings in the top
side at each end of the channel. A differential pressure sensor
(silicon die) is placed on one end of the channel, this
measures the pressure variations at the other end [1] .
Figure 1: Die attachment process: A square of silicone rubber is
dispensed on the flex around the channel opening (1). Then the
pressure sensing die is placed above the opening (2). Wire bonds
are done after the curing of the silicone.
Figure 2: Pressure sensing silicon die attached to a flex print with
silicone rubber. Wire bonds from die to flex pads provide electrical
contact.
A standard face-up bonding approach of the sensor with gold
wire bonds providing electrical contacts was chosen. First, a
RTV (room temperature vulcanizing) silicone rubber was
dispensed around the opening at one end of the channel (see
Figure 1). It is important to dispense the right amount of
98
1
2
adhesive. If too much is applied, it can be pushed into the
opening during die attachment, blocking the channel. Too little
adhesive can cause leaks in the silicone ring. In both cases,
pressure variations at the other end will not be detected
correctly. Then the sensor die was placed on the silicone
rubber. The pressing force is rather low and applied only for a
short time. A few seconds are enough to provide complete
wetting of the sensor die. Higher forces and longer times
increase the probability that the opening will be closed by the
silicone adhesive. The wire bonds were done with a
thermosonic wire bonder after the curing of the silicone
rubber. It is the critical part of the packaging: The wire bonding
parameters like ultrasonic power, clamping force, and time
need to be chosen carefully for this special case. Wire
bonding works best if the device is hard and rigid. Here, the
sensor die is hard, but it lies on a silicone ‘pillow’, allowing the
sensor to vibrate during wire bonding. Furthermore, the
silicone can give way when the bonding tool pushes down on
the sensor pads. Both reduce the energy transfer from the
wire bonding machine to bonding interface. Another issue
deserves attention: Thermosonic wire bonding requires heat.
But the pressure sensor should not be heated above 125 °C
for a long period of time. These constraints have to be
considered when choosing the bonding parameters. On the
flex side, the bonding can be optimized by choosing the
adequate pad metals and thicknesses.
Die attachment and wire bonding are mastered tasks.
Nevertheless, optimization is possible: The silver-finished
metal pads (see Figure 2) on the flex will be replaced by more
suitable metals.
The work was supported by the EU, (project IST-FP6-027540,
IntegramPLUS). CSEM thanks T. Harvey and J. Zhu from
Epigem for the preparation of the flex prints.
•
Epigem Limited, Redcar, UK
[1] N. Schmid, et al., “Pressure Sensing Strip for Rapid
Aerodynamic Testing”, in this report, page 97

Flip Chip Bonding on Polymers – Die Attach and Leak-Tight Sealing
M. Fretz, T. Harvey • , J. Auerswald, N. Schmid, A-C. Pliska, C. Bosshard
A bonding process for sensing elements on PMMA based platforms or vice versa was developed. A ring of anisotropic conductive adhesive (ACA)
forms a cavity between PMMA die and silicon platform. Sealing tests were carried out. This process is suited for dies too small for a micro-gasket
approach.
As a low cost thermoplastic material, PMMA is specially suited
for microfluidic applications and not only for disposable
devices. Often a sample to be inspected must be guided to
the appropriate sensor element through a fluidic channel or
network. Hence, flip chip bonding of the active element on a
PMMA platform is a suitable integration approach. Two tasks
arise: Flip chip bonding must provide electrical contact, and
the sensing area of the chip must be hermetically closed
against the ambient air. Both can be achieved by the use of
anisotropic conductive adhesive (ACA). In this report, the
bonding process of a PMMA die mounted on a silicon platform
with a ring of ACA is described. Electrical connection between
PMMA and silicon was demonstrated before in [1] .
2
1
3
ACA ring
Cavity
4
Figure 1: Die attachment process: The gold studs are placed on the
pads of a PMMA die (1) and flattened (2). Then the flipped die is
mounted on the silicon platform (3), on which a ring of anisotropic
conductive adhesive was dispensed. Finally, the cavity is connected
to the sealing test set up (4).
First, two holes were drilled through the ~5 x 5 x 2 mm 3
PMMA dies. Then, a standard wire bonder was used to place
gold studs on the PMMA (see Figure 1). After gold stud
bumping, a ring of ACA was dispensed on the silicon platform,
followed by the attachment of the flipped PMMA die on the
silicon (Figure 2). The attachment step is critical, because
ACA requires heat (minimum 125 °C) and pressure. But
PMMA will warp under load when exposed to temperatures
above ~100 °C (for more details, see [1] ). Tests were carried
out to evaluate the sealing quality of the ACA: Air was
pumped through the cavity which was connected to a dead
end pressure sensor (for more details, see [2] ).The pressure
was increased until it exceeded 1 bar. Then the leakage of the
cavity was measured for ten minutes, as well as the leakage
of the tubing system alone. The result is plotted in Figure 3.
No breakdown of the pressure was observed within twenty
minutes. The decrease in pressure is due to the tubing and
connectors, as Figure 3 shows. Sealing with ACA can,
therefore, be a suitable approach for microfluidic applications
which require flip chip bonding of small dies.
Metal pads
ACA ring
Drilled holes
Figure 2: 5 x 5 mm 2 PMMA dies mounted on a dummy silicon
platform with anisotropic conductive adhesive.
Figure 3: Leak measurement: The red points (-) depict the pressure
evolution in the tubing system only. The blue crosses (x) include both
the device with the cavity and the tubing.
The work was supported by the EU, (project IST-FP6-027540,
IntegramPLUS). CSEM thanks T. Harvey from Epigem for the
preparation of the PMMA substrates.
•
Epigem Limited, Redcar, UK
[1] M. Fretz, et al., “Flip Chip Bonding on Polymers: A Die
Attachment Method for Low Tg Materials”, CSEM Scientific and
Technical Report 2006, page 88
[2] J. Auerswald, et al., “Bonding of Glass Sensor Chips with Low-
Cost Thermoplastic Microfluidic Scaffolds”, CSEM Scientific and
Technical Report 2006, page 87
99

Optical / Fluidic Integration of Silicon-Based Hollow Waveguides
G. Spinola Durante, J. Auerswald, S. Grossmann, C. Bosshard, M. McNie • , A. S. Wilkinson •
The application of micro/nanotechnology in emerging markets, such as biomedical, healthcare and environmental monitoring requires increasingly
complex levels of functional integration across multiple physical domains. The ability to have optical functions within the fluid core offers significant
potential for bio-sensing with appropriate detection chemistries. Microfluidic channels are simultaneously formed by bonding glass lids to silicon
substrates containing etched waveguides and through-holes to realize fluidic ports. Specific PDMS bonding is being developed and tested with a
traditional shear testing method for checking maximum shear strength and pressure drop method for evaluating fluid-leak tightness. The developed
approach shows good results in terms of gage pressure of the sealing ring that can withstand more than 140KPa.
First trials were made to test the adhesive sealing technology
of integrated hollow waveguides (HWG), but the final goal is to
prove the innovative possibility to integrate optical waveguides
and micro-fluidic channels on wafer scale. The HWG cap
wafer is realized by bonding a metallized glass wafer on top of
the structured silicon wafer, acting both as a fluid channel
enclosure and as a waveguide metallized wall (Figure 1).
Optical and Microfluidic functions are being combined in a
hollow waveguide platform [1] .
Among sealing essential requirements from the application
side are:
• Bio-compatibility in terms of temperature if the sample is
already inside the channel (silicon chip) and in terms of
materials in case the biological sample is transported
throughout fluid motion in the HWG channels
• HWG bonding profile has to be < 1um to match squareshape
optical requirements: zero profile is needed.
• Sealing ring shear stress resistance
• Quasi-hermetic or « leak-proof » sealing ring
The PDMS on-chip direct dispensing method was selected.
Polymer intermediate layer bonding (ILB) proves to be more
flexible not only in terms of maximum processing temperature,
but also in terms of thickness control of the sealing layer.
~7mm
Figure 1: HWG chips bonded with a PDMS sealing ring
This approach is also promising at wafer level since similar
materials can be spin-coated on a glass wafer and UVpatterned.
The shear tests have shown that for a tuned PDMS
curing process PDMS can yield a maximum shear force of
~2.5 Kg on ~25 mm 2 area, with a bonding temperature below
90°C. The fluid leak-tightness has been tested fixing two
standard fluidic connectors to the bonded HWG (Figure 2) and
performing a pressurization of the fluid previously loaded in
the channel and pipes, through a precision pump.
100
~18mm
HWG
Fluidic Port1 Fluidic Port2
Fluidic
Glass wafer on back
Fluidic Port2
Through-holes on Si
Figure 2: HWG bonded chips with assembled fluidic connectors
The results are encouraging since the graph (Figure 3)
indicates a failure of the sealing at gage pressure greater than
140 KPa. This is more than enough for most typical
Microfluidic applications.
Figure 3: Sealing test measurement of HWG sealed chip
This work was supported by the EU, (project IST-FP6-027540,
INTEGRAMplus). CSEM want to thank the EU for its support.
•
QinetiQ Ltd, Malvern (UK)
[1] M. McNie, M. Jenkins, A. S. Wilkinson, A. Turner,
G. Spinola Durante, T. Harvey, T. Cox, C. Bosshard, P. Janus,
“Integration of optical and microfluidic functions in a hollow
waveguide platform”, Proc. Conference on Smart Systems
Integration, Barcelona (E), April 2008

Novel Injection-Free Method for Intraepidermal Delivery of Large Molecular Weight
Drugs
C. Böhler • , T. Bragagna • , A. Heinrich • , S. Summer • , S. Gross • , G. Boer •• , S. Grossmann, K. Krasnopolski, Q. Lai, T. Burch,
M. E. Busse-Grawitz, D. Fengels
Drug patches to deliver substances subcutaneously to replace painful injections are not new, but their application is very limited so far. Many drugs
contain large proteins or water-insoluble hormones, which hardly penetrate the skin or do not at all. A novel system has been developed, that
makes the skin able to absorb a variety of drugs while it is safe and easy to handle and, in addition, does not cause any pain.
Pantec Biosolutions approached CSEM with a vision. The
idea was to develop a small handheld system that creates a
matrix of superficial micro pores within the epidermis. Tissue
damage was to be minimized while damage to blood vessels
and nerve cells must be avoided. The micro pores enable a
large variety of substances contained in a medical patch to
diffuse through the skin barrier and be resorbed by circulation.
A consistent, scalable drug diffusion surface can only be
achieved by a highly controlled microporation process.
Figure 1: Transdermal drug delivery - Patches instead of injections
during hormone therapy for in-vitro fertilization.
The system requirements asked for innovative solutions on
four technology paths - Laser system development, Laser
beam shaping, Laser beam guidance and Skin Layer
detection. To shorten time to market and mitigate risks,
Pantec decided to go into a CTI project together with CSEM
and the IMT.
To achieve the required speed and precision, Pantec decided
to develop a Laser based microporator. The use of a 2.94 μm
Er:YAG Laser aims at an absorption peak of water, enabling
ablation of tissue with very constrained undesired thermal
tissue damage. With a handheld system in mind, Pantec was
able to develop an ultra small, energy efficient Laser system.
The beam shaping is an important part of the system and
forms the interface between Laser energy and tissue. Pantec
conducted clinical studies to learn about the optimum Laser
energy distribution in order to create micro pores optimized for
drug diffusion. The IMT Neuchatel implemented first
prototypes. Diffractive elements made out of silicone showed
promising first results.
Guiding the laser beam requires compact, high-precision
motor control. Within a few seconds, a Laser scanner must
place the Laser spot at a few hundred positions on the skin
surface and come to a full stop at each position within less
than 1 ms at below 10 μm quiescent stability. CSEM
developed a first prototype of the scanner, custom tailored to
the application and superior in size and cost compared to
state of the art solutions.
Figure 2: Compact low-cost Laser scanner (left) with projected
scanning pattern (right)
The skin layer detection consists of a series of measurements
during the ablation process, providing feedback to adopt the
Laser energy. CSEM is currently working close with Pantec
Biosolutions to implement a first compact system. Two
promising methods have been chosen for further investigation.
An optical method measures differences in light scattering
properties of different skin layers while an acoustic method
aims at detecting differences in pressure wave propagation in
skin layers with different water content.
Figure 3: Controlled ablation depth, the goal of Skin Layer Detection
For the patch development, Pantec Biosolutions has two
collaborations, one with a pharmaceuticals company which
supplies the active substances, and the second with a
reputable patch company which has the task to develop and
manufacture the IVF patches.
The creativity, clinical expertise and professional drive of
Pantec Biosolutions, together with the CSEM multidisciplinary
knowhow, have lead to a first working prototype of the device,
the so called LEDDT platform (Laser Easy Drug Delivery
Technology). This work was funded by CTI. CSEM thanks
them for their support.
•
Pantec Biosolutions AG, Ruggell (LI)
••
Institute of Microtechnology, University of Neuchatel (CH)
101

102

TIME AND FREQUENCY
Alain Maurissen
The new time and frequency division of CSEM is an issue
from the transfer July 1st 2007 of the Observatoire de
Neuchâtel activities to the CSEM.
Since the invention of the pendulum clock (C. Huygens 1656),
time and frequency have been the physical quantities that are
measured with the highest precision. It has become a good
strategy to translate other physical quantities into time or
frequency references (f. i. the meter is now defined as the
length of the path travelled by light in vacuum during a time
interval of 1/299 792 458 of a second)
Recently the appearance of new microelectronic components
such as laser diodes and counters/generators working beyond
microwave frequencies has generated a worldwide frenetic
research activity in the domain.
The (r)evolution is such that nowadays the words time and
frequency are so closely associated that they can be used
instead of each other. Measuring time merely translates into
counting cycles of a known frequency (such as the one
provided by an atomic clock therefore called “frequency
standard”). Counting cycles offers the major advantages
inherent to the digital domain (in particular its robustness to
noise perturbations).
The research activities in the new division are perfectly in line
with this trend. CSEM strategy is to take full advantage of the
ongoing research and development in optical components.
The availability of such components will make it possible to
break the microwave barrier (GHz) where technology and
research were stalling and to quickly move towards fully
optical clocks. This means that the available “counters” will
soon operate in the hundreds of terahertz range rather than
the tens of gigahertz range. The direct advantages in terms of
precision and resolution are evident. Less evident is the fact
that one can benefit from these improvements to massively
reduce volume, mass and consumption while still keeping
acceptable performances.
This will approach new domains of applications where the
bulky technologies of today are inadequate (portable devices,
GSMs, watches …).
The all optic compact clock research at the Time and
Frequency Division will take full benefit from the available
technology and research platforms of the other divisions of
CSEM all available under the “one roof” concept.
In 2007, the major efforts of the division were mainly devoted
to:
• Strengthen its position in the development of traditionally
compact clocks, mainly for telecom and space
applications.
• Develop a new domain of research around all optical
clocks and more precisely ultra-compact optical clocks.
• Enhance time of flight and lidars technology, more
particularly in the PRN domain.
The development of the magnetic selection hot Caesium
beam clock is now terminated and has been transferred
successfully to industry so that in 2008 the production of
caesium based atomic frequency standards in Europe will
revive (currently only some US companies produce such
atomic clocks).
The ESA funded Optical Space Caesium Clock research
project terminated in 2007 demonstrates that the goal of
reaching a 10-12 stability at one second is achievable with a
single optical wavelength. This success is paving the way for
new optical clock standards to be embarked on navigation and
deep space sounding satellites. The follow on activity has
already started and aims at demonstrating that such results
can be achieved with flight compatible hardware (see
Figure 1).
Figure 1: Optically pumped Caesium atomic clock for the European
Navigation System Galiléo (Prototype in development)
The development of the Space Active Hydrogen Maser
Engineering Model finished with a full demonstration indicating
that performance of ground masers can be approached with
space compatible technology and constraints (reduction in
dimensions by a factor of approx. 10). The project is now on
hold and waiting its restart in the scope of the development of
a new generation of embarked space hydrogen masers
The latest developments around the lidar demonstrated that
PRN modulation of commercially available laser diode leads
to eye safe lidars capable of detecting targets at 8 km during
daytime. Together with the positive experience accumulated
with other lidar types in EU projects, these results gives a
boost in the planning of this activity at CSEM.
103

PRN-cw Backscatter Lidar Prototype
V. Mitev, R. Matthey, M. Haldimann
In the frame of this activity we have realized a prototype of a backscatter lidar, based on the Pseudo-Random Noise modulation of a continuous
wave diode laser (PRN-cw). The realized prototype is a compact and robust sensor, capable of detecting solid surfaces and cloud base. Its
detection performances are demonstrated for ranges from 600 m till 8000 m.
The motivation in the development of PRN-cw lidars is based
on the use of cw laser sources in range-resolved remote
sensing. Such lidars inherit a number of advantages from the
cw laser: high power-efficiency, long life, robustness and
compactness, and eye-safety. These advantages make the
PRN-cw lidar a potential candidate for space missions in
landing, altimetry, surface topography mapping, approaching
and docking, collision avoidance, cloud and atmospheric
sensing, etc. There are industrial applications that will benefit
from the eye-safety of the operation, as well as the compact
and durable design – traffic control, collision avoidance, etc.
The presented activity is supported by ESA and included the
realisation of a compact PRN-cw lidar based on standard
commercial components, as well as a set of tests for detection
of hard target surfaces and cloud-base.
Figure 1: View of the reported PRN-cw lidar mounted for testing on a
pointing table. The dimensions of the lidar main-frame are as follows:
695 mm x 300 mm x 160 mm.
The lidar is based on amplitude modulated laser diode with
mean power of 400 mW. The laser diode is connected by
optical fiber to the transmitting telescope. The transmitter and
the receiver telescopes are assembled in a common
mechanical frame, also supporting the detector and the
electronics blocks for digitalisation and acquisition –Figure 1.
The PRN sequence is with bin-duration of 50 ns (20 MHz
modulation frequency). The received backscatter signal is
detected by an APD, amplified by a variable-gain amplifier and
digitalized. The digitalisation is performed with 80 MHz
sampling rate, i.e., with 4 times oversampling and follow-on
decimation of 4 times. In this way the sampling frequency of
80 MHz relaxes the requirements for the low-pass anti-alias
filter without degradation of the range resolution.
The generation of the PRN code, the signal accumulation and
decimation, are performed in a FPGA-based system. The
operation control of the lidar is carried by a PC connected via
USB interface to the FPGA. The calculation of the crosscorrelation
function is also performed in this PC, by a code
based on FFT procedure.
104
The measurements at shorter range are possible with an
extremely small number of sequences and respectively short
integration times. Figure 2 shows one example of detection of
a surface at 739 m, achieved daytime with integration time of
1 millisecond. The test demonstrated that the lidar is capable
of detecting surfaces (targets) at ranges till 8 km daytime.
Figure 2: Cross-correlation function of backscattered signal from
surfaces at 739 m, daytime; Integration time is 1.024 ms.
Figure 3 presents an example of cross-correlation function for
detection of the backscatter signal from cloud-base. The
cloud-base detection is demonstrated for cloud altitudes from
400 m till 3200 m with integration time varying from 0.05 s to
30 s. The measurements were performed also daytime.
Figure 3: Example of cross-correlation function of cloud-base
backscattered signal. Integration time is 10s, daytime.
Numerical tools for performance simulation of the PRN-cw
lidar with analog detection have been realized. The
comparison with the test measurements shows the adequacy
of the numerical model, allowing the simulation and
assessment of future application scenarios for advanced
PRN-cw lidars.

Space Hydrogen Active Maser
S. Zivanov, C. Weber
One of the two frequency standards that will be part of the Atomic Clock Ensemble in Space (ACES) payload to be flown on the International Space
Station (ISS) is an active Space Hydrogen Maser (SHM) mandatory for its ultimate frequency stability performance in the mid-term range
(3 s ≤ τ ≤ 3000 s). The Engineering Model developed in CSEM reaches the weight of the 35 kg SHM, the lightest ever built active maser.
The SHM instrument is divided into two principal functional
packages, the Physics Package (Figure 1), that provides the
actual atomic oscillator, and the Electronics Package
(Figure 2), that provides the atomic signal processing circuits,
parameter control functions, telemetry and telecommand.
The Physics Package is made of the microwave cavity and
magnetic shield assembly, the electronics unit and several
integrated peripherals like the hydrogen distribution assembly
and the ion pumps.
Figure 1: The photo of the Engineering Model and cross-section
schematics view of SHM instrument:
1: Microwave cavity and shields assembly; 2: Hydrogen-vacuum
assembly; 3: Ions pumps; 4: Low noise RF amplifier 5: External
fixation structure; 6: Hydrogen distribution assembly.
In order to fulfill miniaturization, the sapphire resonator acts as
a "dielectric load" reducing the size of the microwave cavity
and serving at the same time as the storage container for the
atomic hydrogen. The microwave cavity is made of titanium
and tuned mechanically, thermally and electrically at the
hydrogen hyperfine frequency. The atomic storage bulb is a
sapphire cylinder of 1.7 liters bonded to the titanium cavity
covers and Teflon coated. This volume, comparable to a full
size maser design, and the Teflon coating technology
developed at CSEM reach a high atomic signal and operating
quality factor. The hydrogen atomic beam and storage bulb
are maintained under high vacuum with an ensemble of
getters and ion pumps. The getter ensemble allows a vacuum
autonomy of 10 days without electrical power and an
instrument life time of more than 5 years. The thermal
regulation is based on three pairs of concentric heaters
regulating the microwave cavity temperature with a stability of
1 mK. The heat is evacuated by conductance through the
mechanical structure only. An Automatic Cavity System
(ACT), based on a sampled interrogation scheme, prevents
SHM drifts due to the cavity pulling. The magnetic shielding is
enhanced with an active compensation control loop. A step
further in the direction of the size reduction is the removal of
the external vacuum enclosure which provides the so called
“thermal vacuum”. This vacuum will be provided instead and
directly by the “space vacuum”, given that the SHM is
operating in the space environment.
The Electronics Package is composed of an RF unit in charge
of frequency locking the local quartz oscillator on the
hydrogen clock transition frequency as well as frequency
locking the microwave cavity using the ACT, of providing the
proper microwave frequency to the hydrogen dissociation
power amplifier, and finally of delivering a stable 100 MHz
signal to the ACES payload. The Control Unit and the Power
Supply Unit provide and/or control the necessary powers for
an optimal operation of SHM. Finally, the Control Unit
interfaces to the ACES payload in terms of telecommands and
telemetries.
Figure 2: The functional block diagram of the SHM Electronics
Package
The main objective of the current development is to perform
an end-to-end performance demonstration, to be used as a
stepping stone for pursuing the development of the SHM and
aiming at the delivery of the SHM Proto Flight Model (PFM).
105

106

COMLAB
Alex Dommann
CSEM develops, produces and integrates custom or standard
innovative microsystems (sensors, actuators and their
integration into micro-systems) by exploiting its advanced
technologies to provide new integrated solutions to industrial
and institutional customers. Targeted markets and
applications include automotive, telecommunications, security,
health care, biotechnology and environment − markets in
which system miniaturization and integration is a must.
In close collaboration with the regional industry, research
organizations, universities and the political authorities, the
market for small volume production has been selected. Since
the region between Lausanne and Neuchatel is already home
to a substantial, successful MEMS cluster and CSEM has a
rich portfolio of MEMS solutions to offer, it was obvious to
increase the Comlab activities.
The global objective of Comlab is to supply a technology
support for the R&D and production projects of CSEM, IMT
(University of Neuchatel) and other publically funded R&D
laboratories in the field of micro- and nanosystems like the
CMI at the EPFL in Lausanne.
CSEM concentrates its cleanroom activities towards reliable
and qualified processes rather than developing absolute
unique processes. Thus, CSEM is complementary to the CMI
and IMT environment and also plays a role as an industrial
company.
Within the Subprogram “Foundry Services”, the Comlab
organized the processing of the structures within the different
programs of the divisions. Applications were minimal invasive
medical instruments, MEMS for space, watch parts, fluidic
channels and many other structures needed for evaluating the
possibilities of the technology. The laboratory also fabricates
prototypes and demonstrators that are used in advanced R&D
programs of the industry. The flexibility of Comlab for the
fabrication of small quantities of prototypes has proven to be
attractive to industry for their R&D programs. To improve the
power and the reliability of the foundry services, a quality
manager with industrial experiences was hired.
Within the Subprogram “Process Development” the Comlab
developed new processes needed in research programmes as
well as for the small volume production.
The Subprogram “Quality Control” is focusing on a key
issue for the industrialization of MEMS. Quality control,
however, needs attention at every development step.
Reliability, testability as well as aging are key words which are
essential to the industrialization of MEMS. CSEM, in
collaboration with IMT (group of Prof. N.F. de Rooij) has
moved one step further to industrialization by combining the
service of the Micro- and Nanoscopy (SMN, Dr. Massoud
Dadras from IMT) with an additional X-ray service headed by
Dr. Antonia Neels to a true quality management lab. Quality
control is one way to differentiate CSEM from the Universities.
249 samples were measured and analyzed by the new X-ray
service during the year 2007 and 321 structure analyses were
carried out. The X-ray service was engaged in different
applications for European Projects and projects on long term
stability/aging of MEMS by HR-XRD.
The goal of the X-ray Diffraction Laboratory for MEMS is to
develop a test procedure for MEMS devices that:
• Produce data that will help the system designers
understanding of ‘end-of-life’ characteristics
• Can be adapted to the failure modes of MEMS devices.
Can help to find correlation of the defect analysis with
mechanical properties for Si based micro systems.
• Life time estimations of specific Si based devices under
different environmental conditions.
• To develop a quality control tool based on X-ray defect
analysis.
HRXRD measures the strain of a crystal with high resolution.
This non destructive method obtains quantitative data on the
strain present in a sample. CSEM uses HRXRD to assess the
strain in DRIE etched processed silicon beams. Strain
deforms the silicon beam leading to an appreciable sample
curvature which is detected via the broadening of the X-ray
peak in a “rocking-curve” measurement.
In the future the collaboration between IMT and EPFL will be
enforced.
107

Quality Control
A. Dommann, A. Ibzazene, A. Neel
Quality control is one way to differentiate CSEM from the Universities. Substantial efforts have been undertaken to bring this capability to an
internally recognized performance level.
249 samples were measured and analyzed by the new X-ray
service during the year 2007. The X-ray service was engaged
in:
• A CTI Project with OC Oerlikon at Balzers
• Different applications for European projects
• Projects on long term stability / aging of MEMs by HR-
XRD
High resolution X-ray diffraction (HRXRD) is routinely used for
the investigation of composition, strain, orientation and overall
quality of thin films and bulk crystalline structures.
A high-resolution X-ray diffractometer measures the strain of a
crystal. This is an accurate, non destructive method applied in
the field of MEMS to obtain quantified results on the crystalline
disorder. Aging of micromachined silicon actuators often goes
along with a change of the strain profile. HRXRD is therefore
an optimal analysis tool for aging investigation on MEMS. For
the X-ray measurements a Panalytical MPD high-resolution
diffractometer was used. Typically, a strong argument to use
monocrystalline material and, especially, silicon is its potential
resistance against aging. However, quantified results of this
fact are rarely published [1, 2] . Schweitz [3] has described
methods to characterize mechanically the properties of thin
films. Some of them may be used for aging studies.
Comparison between theoretical fracture values and real
measurements show more than a factor of 10 differences
between differently prepared structures. The reasons are
manifold, however they are related to the surface roughness
as well as to the defect concentration of the etched surfaces
due to the ion bombardment [4] . Aging of a MEMS results in a
change of the crystal strain profile. Therefore, aging of a
crystal can be documented by this method as a change of the
strain profile) [5] . In addition, the X-ray standing wave method
(XSW) and reciprocal space mapping (RSM) [6] permit to
characterize the amount of crystalline defects introduced by
cycling and by manufacturing of MEMS devices. The surface
roughness can be measured by AFM methods.
The goal of the X-ray Diffraction Laboratory for MEMS is to
develop a test procedure for MEMS devices that:
• Produce data that will help the system designers
understanding of ‘end-of-life’ characteristics
• Can be adapted to the failure modes of MEMS devices
HRXRD measures the strain of a crystal with high resolution
(Figure 1). This non destructive method obtains quantitative
data on the strain present in a sample. CSEM uses HRXRD to
assess the strain in DRIE etched processed silicon beams.
Strain deforms the silicon beam leading to an appreciable
sample curvature which is detected via the broadening of the
X-ray peak in a “rocking-curve” measurement.
108
mirror
X
X-ray source
primary beam
monochromator
Figure 1: HRXRD measuring setup
sample
diffracted
beam analyzer
(optional)
φ
detector
ω
χ
[1] S. Arney, Designing for MEMS Reliability, MRS Bulletin, April
2001, 296
[2] R. Shea Herbert, Reliability of MEMS for space applications,
Proc. SPIE Int. Soc. Opt. Eng. 6111, 61110A (2006)
[3] J.-Å Schweitz, Mechanical Characterization of Thin Films by
Micromechanical Techniques, MRS Bulletin, XVII, 7 (1992),
34-45
[4] E. Mazza and J. Dual, Mechanical behavior of a µm-sized single
crystal silicon structure with sharp notches. J. Mechanics and
Physics of Solids 47 (1999), 1795-1821
[5] T. Vreeland Jr, A. Dommann, C.-J. Tsai and M.-A Nicolet, X-ray
Diffraction Determination of Stresses in Thin Films, Res. Soc.
Symp. Proc., Vol. 130 (1989), 3-12
[6] A. Dommann, A. Enzler, N. Onda, Advanced X-ray analysis
Techniques to Investigate Aging of Micromachined Silicon
Actuators for space Application, Microelectronics Reliability, 43
(2003), 1099-1103
2θ

ANNEXES
Publications
[1] L. Aeschimann, F. Goericke, J. Polesel-Maris,
A. Meister, T. Akiyama, B. Chui, U. Staufer,
R. Pugin, H. Heinzelmann, N.F. de Rooij, W.P. King,
P. Vettiger
"Piezoresistive scanning probe arrays for operation
in liquids"
Journal of Physics: Conference Series, 61 (2007) 6
[2] T. Akiyama, L. Aeschimann, L. Chantada,
N.F. de Rooij, H. Heinzelmann, H.-P. Herzig,
O. Manzardo, A. Meister, J. Polesel-Maris, R. Pugin,
U. Staufer, P. Vettiger
"Concept and Demonstration of Individual Probe
Actuation in Two-Dimensional Parallel Atomic Force
Microscope System"
Japanese Journal of Applied Physics, 46 (2007)
6458
[3] N. Blondiaux, S. Zürcher, M. Liley, N. D. Spencer
"Fabrication of Multiscale Surface-Chemical
Gradients by Means of Photocatalytic Lithography"
Langmuir, 23 (2007) 3489
[4] B. Büttgen, M.-A. El Mechat, F. Lustenberger,
P. Seitz
"Pseudo-Noise Optical Modulation for Real-Time
3D-Imaging with Minimum Interference, "
IEEE Transactions on Circuits and Systems, 54
(October 2007) 2109
[5] B.W. Chui, L. Aeschimann, T. Akiyama, U. Staufer,
N.F. de Rooij, J. Lee, F. Goericke, W.P. King,
P. Vettiger
"Advanced temperature compensation for
piezoresistive sensors based on crystallographic
orientation"
Review of Scientific Instruments, 78 (2007) 43706
[6] A. Dommann, G. Kotrotsios, A. Neels
"MEMS Reliability and Testing"
MST News, 3/07 (2007) 33
[7] P. Drobinski, V. Mitev, et al.
"Föhn in the Rhine Valley during MAP: A review of
its multiscale dynamics in complex valley geometry"
Quarterly Journal of the Royal Meteorological
Society, 133-B (2007) 897
[8] M. Fretz, T. Harvey, A-C. Pliska, C. Bosshard
"Flip-Chip Bonding on Polymers: A Die Attachment
Method for Low Tg Materials"
MST News, 4 (2007) 27
[9] V. Friedli, Ch. Santschi, J. Michler, P. Hoffmann,
I. Utke
"Mass sensor for in situ monitoring of focused ion
and electron beam"Applied Physics Letter, 90
(2007)
[10] P. Glocker
"Mikromontage mit Innovationspotential"
A&D Select Robotik&Automation, 9 (2007) 36
[11] H.F. Knapp
"Precise Handling of Liquids and Cells"
MST News, 5 (2007) 37
[12] C. Kottler, F. Pfeiffer, O. Bunk, C. Grünzweig,
J. Bruder, R. Kaufmann, L. Tlustos, H. Walt, I. Briod,
T. Weitkamp, C. David
"Phase contrast X-ray imaging of large samples
using an incoherent laboratory source"
Phys. Stat. sol. (a), 204 (2007) 2428
[13] Q. Lai, T. Burch, S. Grossmann, A. Stump,
K. Krasnopolski, M. Busse-Grawitz, D. Fengels,
C. Böhler, T. Bragagna, A. Heinrich, S. Gross,
S. Summer, B. Nussbaumer, G. Boer
"Medizintechnik – Spielgrund für Innovation"
STZ/SWISS ENGINEERING, 10 (2007) 31
[14] G. Martucci, V. Mitev, R. Matthey, H. Richner
"Comparison between Backscatter Lidar and
Radiosonde Measurements of the Diurnal and
Nocturnal Stratification in the Lower Troposphere"
Journal of Atmospheric and Oceanic Technology, 24
(2007) 1231
[15] E. Onillon
"Europe’s New Weather Satellite"
dSPACe News, (February 2007) 14
[16] C. Piguet
"Consommation statique: modèles, évolutions et
perspectives "
Techniques et Sciences Informatiques, RSTI série
TSI, 26, n° 5/07 (May 2007) 623
[17] C. Piguet
"Low-Power Design of Systems on Chip "
Digital Design and Fabrication, edited by Vojin
Oklobdzija, SPI Publishers, (2007) 39464
109

[18] A.-C. Pliska, C. Bosshard
"Adhesive bonding of passive optical components"
Micro and Opto-Electronic Materials and Structures -
Physics, Mechanics, Design, Reliability and
Packaging, 1 (2007) 487
[19] J. Polesel-Maris, L. Aeschimann, A. Meister,
R. Ischer, E. Bernard, T. Akiyama, M. Giazzon,
P. Niedermann, U. Staufer, R. Pugin, N.F. de Rooij,
P. Vettiger, H. Heinzelmann
"Piezoresistive cantilever array for life sciences
applications"
Journal of Physics: Conference Series, 61 (2007)
955
[20] J. Ramm, M. Ante, H. Brändle, A. Neels,
A. Dommann, M. Döbeli
"Thermal stability of thin film corundum-type solid
solutions of (Al1-xCrx)2O3 synthesized under low
temperature non equilibrium conditions"
Engineering Materials, 9 (2007) 604-608
[21] M. Roerdink, J. Pragt, I. Korczagin,
M.A. Hempenius, T. Stöckli, Y. Keles, H.F. Knapp,
C. Hinderling, G.J. Vancso
"Templated Growth of Carbon Nanotubes with
Controlled Diameters Using Organic-Organometallic
Block Copolymers with Tailored Block Lengths"
Journal of Nanoscience and Nanotechnology, 7
(2007) 1052
[22] A. S. Roy, C. C. Enz, J.-M. Sallese
"Source–Drain Partitioning in MOSFET"
IEEE Trans. Electron Devices, 54, Nr. 6 (June 2007)
1384
Proceedings
[1] J. Auerswald, P. Niedermann, F. Dias, H. Keppner,
J. Nestler, K. Hiller, T. Gessner, H.F. Knapp
"Bonding of SPR Sensors on Glass Chips to
Thermoplastic Microfluidic Scaffolds"
Smart Systems Integration Conference, T. Gessner,
Paris, FR, March 07, 153
[2] J. Ayadi, H. Zhan, J. R. Farserotu
"Maximum Likelihood Time of Arrival Estimation for
UWB Signals"
IEEE International Symposium on Signal Processing
and its Applications, IEEE ISSPA, Sharjah, AE,
February 2007
110
[23] A. S. Roy, C. C. Enz
"Analytical Modeling of Large-Signal Cyclo-
Stationary Low-Frequency Noise With Arbitrary
Periodic Input"
IEEE Trans. Electron Devices, 54, 2537
[24] A. S. Roy, C. C. Enz, J.-M. Sallese
"Modeling in Lateral Nonuniform MOSFET"
IEEE Trans. Electron Devices, 54, 1994
[25] N. Virag, R. Sutton, R. Vetter, T. Markowitz,
M. Erickson "Prediction of vasovagal syncope from
heart rate and blood pressure trend and variability:
Experience in 1,155 patients"
Heart Rhythm, 4 (November 2007) 1377
[26] C. Voigt, B. Kärcher, H. Schlager, C. Schiller,
M. Krämer, M. de Reus, H. Vössing, S. Borrmann,
V. Mitev
"In-situ observations and modeling of small nitric
acid-containing ice crystals"
Atmospheric Chemistry and Physics, 7 (2007) 3373
[27] U. Yodprasit, C. C. Enz, P. Gimmel
"Common-mode Oscillation in Capacitive Coupled
Differential Colpitts Oscillators"
Electronics Letters, 43, Nr. 21 (October 2007) 1127
[3] J. Ayadi, H. Zhan, J. R. Farserotu
"Ranging Algorithms for UWB Communication
Systems"
International Conference: Sciences of Electronic,
Technologies of Information and
Telecommunication, SETIT, Hammamet, TN,
March 2007
[4] M.-A. El Mechat, B. Büttgen
"Realization of Multi-3D-TOF Camera Environments
Based on Coded-Binary Sequences Modulation"
Optical 3-D Measurement techniques VIII, Grün,
Kahmen, Zurich, CH, July 2007, 26
[5] M. El-Khoury, J. Solà I Caros, V. Neuman, J. Krauss
"Portable SpO2 Monitor: A Fast Response
Approach"
IEEE Portable 2007, IEEE, Orlando, US,
March 2007

[6] M. El-Khoury
"Body Sensor Networks and Portable Monitoring
Systems"
IEEE Portable 2007, IEEE, Orlando, US,
March 2007
[7] J. R. Farserotu
"Short range wireless connectivity for health and
wellness-Draft V0.1"
ETSI EP eHealth, ETSI, Sophia Antipolis, FR,
December 2007
[8] M. Fretz
"Simulation of Hygro Swelling Induced Stresses in
Flip Chip Interconnects in a Stress-Sensitive Chipon-Board
Configuration"
Comsol Conference 2007, M. Fretz, Grenoble, FR,
October 2007, CD proceeding
[9] J. Gerrtis, J. R. Farserotu
"FM-UWB: A low Complexity Constant Envelope
LDR UWB Communication System"
IEEE802.15, Wireless Personnal Area Networks,
Study group BAN, WPAN, July 2007
[10] E. Grenet
"Embedded high dynamic range vision system for
real-time driving assistance"
Sensorik für Fahrerassistenzsysteme, Heilbronn,
DE, September 2007
[11] C.A. Griffiths, S. Bigot, E. Brousseau, M. Heckele,
J. Nestler, J. Auerswald
"Polymer inserts tooling for prototyping of micro
fluidic components in micro injection moulding"
4M 2007 Conference on Multi-Material Micro
Manufacture, S. Dimov, W. Menz, Y. Toshev,
Borovets, BG, October 2007, 113
[12] T. Heldal, T. Volden, J. Auerswald, H.F. Knapp
"Embedded Low-Voltage Micropump Based Using
Electroosmosis of the Second Kind"
NSTI Nanotech 2007, 10th Annual Nanotechnology
Conference and Trade Show, The Nano Science
and Technology Institute (NSTI), USA, Santa Clara,
US, May 2007, Vol. 3, 268
[13] S. Henein, M. Stampanoni, U. Frommherz, M. Riina
"The Nanoconverter: a novel flexure-based
mechanism to convert microns into nanometers"
7th International Conference of the European
Society for Precision Engineering &
Nanotechnology, EUSPEN, Bremen, DE, May 2007
[14] K. Hiller, T. Gessner, J. Nestler, J. Gavillet, S. Getin,
E. Quesnel, S. Martin, G. Dellapierre, J. Soechtig,
G. Voirin, L. Buergi, J.
"Integration Aspects of a Polymer Based SPR
Biosensor with Active Microoptical and Microfluidic
Elements"
Smart Systems Integration Conference, T. Gessner,
Paris, FR, March 07, 295
[15] H-B. Li, J. Shwoerer, Y.M. Yoon, J. R. Farserotu
"IEEE802.15.6 Regulation Subcommittee Report,
IEEE802.15, Wireless Personnal Area Networks"
IEEE802.15, Wireless Personnal Area Networks,
IEEE P802.15-07-0939-00-OBAN, WPAN, Atlanta,
US, November 2007
[16] G. Martucci, R. Matthey, V. Mitev, H. Richner
"Lidar determination of the frequency of variations of
the boundary-layer top"
IGARSS 2007, Barcelona, SP, 23-27 July 2007,
Paper 1107
[17] V. Mitev, M. Sato, T. Ebizuzaki, Y. Takizawa,
Y. Kawasaki, R. Matthey
"Atmospheric Monitoring System of JEM-EUSO
Mission"
30th International Cosmic Ray Conference, Merida,
MX, July 3 - 11, 2007, Paper 0846
[18] V. Mitev, R. Matthey, G. Martucci, V. Yushkov,
N. Sitnikov, A. Lukyanov, E. Lapshova,
A. Ulanovsky, F. Ravegnani
"Evidences for vertical transport connected to cirrus
clouds formation in the tropical UTLS, observed with
stratospheric aircraft 'Geophysica' "
European Geosciences Union (EGU) General
assembly, Vienna, AU, 15-20 April 2007,
AS1.09-1TH1P-0022
[19] J. Nestler, A. Morschhauser, K. Hiller, J. Auerswald,
H.F. Knapp, T. Otto, T. Gessner
"Fully Integrated Polymer Based Microfluidic Pumps
and Valves in Lab-on-Chip Systems for Point-of-
Care Use"
Smart Systems Integration Conference, T. Gessner,
Paris, FR, March 07, 565
[20] J. Nestler, A. Morschhauser, K. Hiller, S. Bigot,
J. Auerswald, J. Gavillet, T. Otto, T. Gessner
"Electrochemical microfluidic pumps based on super
absorbing polymers"
11th International Conference on Miniaturized
Systems for Chemistry and Life Sciences
(MicroTAS), J.-L. Viovy, P. Tabeling, S. Descroix,
L. Malaquin, Paris, FR, October 2007, 1504
111

[21] E. Onillon, P. Theurillat, A. O’Hare, P. Spanoudakis,
P. Schwab
"Mechanical Slit Mask Mechanism Breadboard for
the MOSFIRE instrument of the KECK Telescope
Spectrometer"
IEEE/ASME International Conference on Advanced
Intelligent Mechatronics, AIM 2007, Zurich, CH,
September 2007
[22] J. Osmond, G. Isella, D. Chrastina, R. Kaufmann,
H. von Känel
"Ge/Si (100) heterojunction photodiodes fabricated
from material grown by low energy plasma
enhanced chemical vapor deposition"
5th International Conference on Silicon Epitaxy and
Heterostructures (ICSI-5), to be published in Thin
Solid Films, Elesevier, Marseille, FR, May 2007
[23] A. Perret, K.D. Lang, G. Poupon
"Euripides White Book"
[24] C. Pickering, M. McNie, C. Reeves, T. Harvey,
T. Ryan, C. Bosshard, H.F. Knapp, G. Schröpfer,
F. von Germar, T. Bauer, P. Janus, P. Gabriec,
C. Moldovan, B. Firtat, A. Richardson
"Multi-domain and multi-technology integration for
next generation MNT products"
Smart Systems Integration Conference, Paris, FR,
March 07, 73
[25] C. Piguet
"Histoires des microprocesseurs horlogers 2/3"
Bulletin de la Société Suisse de Chronométrie, 54
(May 2007) 31
[26] C. Piguet
"Histoires des microprocesseurs horlogers 3/3"
Bulletin de la Société Suisse de Chronométrie, 55
(September 2007) 33
[27] A.-C. Pliska, R. Bauknecht, R. Krähenbühl,
A. Peterhans, A. Stump, S. Aiterrami, C. Bosshard,
J. Kunde
"Compact 90°multi-fiber releasable connection"
Smart Systems Integration Conference, T. Gessner,
Paris, FR, March 07, 223
[28] J. Rousselot, A. El-Hoiydi, J-D. Decotignie
"On the Problem of Near-Far Interference with
Impulse Ultra Wide Band radios"
European Ultra Wide Band Radio Technology
Workshop, UWB 2007, Grenoble, FR, May 2007
112
[29] J. Rousselot, A. El-Hoiydi, J-D. Decotignie
"Performance evaluation of the IEEE 802.15.4A
UWB physical layer for Body Area Networks"
12th IEEE Symposium on Computers and
Communications, ICC 2007, Aveiro, PT, July 2007,
969
[30] P.-F. Rüedi, E. Grenet, F. Lustenberger
"Battery powered high dynamic range vision system"
ISCAS, New Orleans, US, May 2007, 1200
[31] P.-F. Rüedi
"High dynamic range vision sensor for embedded
applications"
Image sensor analog and digital on-chip processing,
Toulouse, FR, November 2007
[32] P. Seitz, S. Beer, Y. Delley
"Smart pixel array for the simultaneous detection of
phase and amplitude envelope, enabling real-time
nanometer-precision OCT"
Frontiers of Electronic Imaging, P. Seitz, Munich,
DE, June 2007, 76
[33] P. Seitz
"Optical Biochips"
4th Optoelectronic and Photonic Winter School on
Biophotonics, L. Pavesi, Trento, IT, March 2007, 14
[34] P. Seitz
"Photon-Noise Limited Distance Resolution of
Optical Metrology Methods"
SPIE Conference on Optical Metrology, W. Osten,
Munich, DE, June 2007, 66160D
[35] P. Seitz
"The history of optical time-of-flight techniques for
3D imaging "
Frontiers of Electronic Imaging, P. Seitz, Munich,
DE, June 2007, 62
[36] P. Seitz
"Tiens, vous voulez faire une carrière scientifique"
Atelier du Laboratoire Européen Associé en
Microtechnique, S. Grassi, Arc-et-Senans, FR,
September 2007, 50
[37] J. Solà I Caros, O. Chételat, J. Krauss
"On the reliability of pulse oximetry at the sternum"
29th Annual International Conference of the IEEE
Engineering in Medicine and Biology Society, IEEE
EMBC 2007, Lyon, FR, August 2007

[38] J. Solà I Caros, O. Chételat
"Combination of multiple light paths in pulse
oximetry: the finger ring example"
29th Annual International Conference of the IEEE
Engineering in Medicine and Biology Society, IEEE
EMBC 2007, Lyon, FR, August 2007
[39] J. Solà I Caros, O. Chételat
"Opto-electric cardiovascular monitoring"
SSBE 2007, CSEM, Neuchatel, CH, August 2007
[40] P. Spanoudakis, P. Schwab, S. Droz,
J-P. Jeanneret, S. Henein
"Flexure-based micro-gripper for robotic
applications"
7th International Conference of the European
Society for Precision Engineering &
Nanotechnology, EUSPEN, Bremen, DE, May 2007
[41] G. Voirin, G. Dudnik, J. Luprano
"Advanced e-textiles for firefighter and civilian
victims"
3rd Global Plastic Electronics Conference &
Showcase, Plastic Electronics Foundation,
Frankfurt, DE, October 2007
[42] D. Wehrle, D. Feriencik, A. Hutter, L. Garcia,
P. Pelissou, F.J. Lopez Hernandez, K. Pribil,
I. Hernandez Velasco, P. Plancke, R. Magness
"The Wireless Intra-spacecraft Data Handling
Demonstrator Development for the European Space
Agency"
DAta Systems In Aerospace, DASIA 2007, Naples,
IT, May-June 2007
[43] Q. Xu, J. R. Farserotu, J.-F. Zürcher, A. Skrivervik
"Broadband small array antenna for high altitude
platforms applications"
18th Annual IEEE International Symposium on
Personal, Indoor and Mobile Radio
Communications, IEEE PIMRC 2007, Athens, GR,
September 2007
Conferences and Workshops
J. Auerswald, P. Niedermann, F. Dias, H. Keppner,
J. Nestler, K. Hiller, T. Gessner, H.F. Knapp
"Smart Systems Integration Conference"
Assembly and Interconnect Technologies, Paris,
FR, March 2007
J. Ayadi
"IEEE International Symposium on Signal
Processing and its Applications"
IEEE ISSPA, Sharjah, AE, February 2007
[44] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec
"A novel maximum likelihood estimation of
superimposed exponential signals in noise and ultrawideband
application"
19th Annual IEEE International Symposium on
Personal, Indoor and Mobile Radio
Communications, IEEE PIMRC 2007, Athens, GR,
September 2007
[45] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec
"High Resolution Impulse Radio Ultrawideband
Ranging"
IEEE International Conference on Ultra-Wideband,
ICUWB2007, Singapore, SG, September 2007
[46] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec
"Ultra Wideband Ranging under Multi-User
Environments Based on Hidden Markov Model"
10th International Symposium on Wireless Personal
Multimedia Communications, WPMC 07, Jaipur, IN,
December 2007
[47] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec
"Impulse Radio Ultra-Wideband Ranging under
Mulit-User Environments Based on Hidden Markov
Model"
10th International Symposium on Wireless Personal
Multimedia Communications, WPMC 07, Jaipur, IN,
December 2007
J. Ayadi
"International Conference: Sciences of Electronic,
Technologies of Information and
Telecommunication"
SETIT, Hammamet, TN, March 2007
113

A. Bonfiglio, N. Carbonaro, C. Chuzel, D. Curone,
G. Dudnik, F. Germagnoli, D. Hatherall,
J.-M. Koller, T. Lanier, G. Loriga, J. Luprano,
G. Magenes., R. Paradiso, A. Tognetti, G. Voirin,
R. Waite
"Managing catastrophic events by wearable mobile
systems"
MobileResponse 20007, International Workshop on
Mobile Information, Sankt Augustin, DE,
February 2007
N. Blondiaux, S. Zürcher, S. Morgenthaler,
R. Pugin, N.D. Spencer, M. Liley
"Fabrication of multiscale, surface chemical and
surface structure"
SAOG-GSSI, 23rd annual meeting, Fribourg,
Switzerland, January 2007
C. C. Enz, J. Baborowski, J. Chabloz, M. Kucera,
C. Muller, D. Ruffieux, N. Scolari
"Ultra Low-Power MEMS-based Radio for Wireless
Sensor Networks"
European Conference on Circuit Theory and
Design (ECCTD), Sevilla, ES, August 2007
J. Chabloz, D. Ruffieux, A. Vouilloz, P. Tortori,
F. Pengg, C. Muller, C. C. Enz
"Frequency Synthesis for a Low-Power 2.4 GHz
Receiver Using a BAW Oscillator and a Relaxation
Oscillator"
European Solid-State Circuit Conference
(ESSCIRC), Munich, DE, September 2007
O. Chételat
"Continuous multiparameter health monitoring"
Colloque Médecine Aerospatiale, Genève, CH,
June 2007
A. Dommann
"Acta Materialia Gold Medal Workshop;
Commercialization of Nanotechnology"
2007 E-MRS Fall Meeting, Wasaw, PL,
September 2007
A. Dommann
"Aging measurements on microstructures"
HRXRD Workshop, CSEM, Neuchatel, CH,
August 2007
A. Dommann
"Coating technologies for the watch industry"
CCMX-Conference, Lausanne, CH, June 2007
A. Dommann
"Coatings and MEMS for Lifesciences"
Lohmann & Rauscher Science Day, Bonn, DE,
February 2007
114
A. Dommann
"Companies on the NANO sector"
STAB Scientific Technological Advisory Board,
Vienna, Vienna, AU, December 2007
A. Dommann
"Crystallography on perfect crystals"
10th Anniversary of the BENEFRI Crystallography
Service, Neuchatel, CH, November 2007
A. Dommann
"CSEM, a strategic Partner of Ciba"
Ciba R&D Conference 2007, Basel, Basel, CH,
November 2007
A. Dommann
"Future of Comlab"
5th European Mechatronics Meeting, Grand-
Bornand, FR, June 2007
A. Dommann
"Innovative X-Ray techniques to characterize VLSI"
SIMTech - Joint Swiss-Singapore Workshop on
Sensors for Harsh Environments, Singapore, SG,
January 2007
A. Dommann
"Long term stability of MEMS"
NanoScience 2007, Lichtenwalde/Sachsen, DE,
October 2007
A. Dommann
"MEMS for Cars"
VW Seminar, Wolfsbrurg, DE, March 2007
A. Dommann
"MEMS Reliability for Space"
First CEAS European Air and Space Conference,
Berlin, DE, September 2007
A. Dommann
"More than Moore and MEMS"
ENIAC Initiative, IBM Research Centre,
Rüschlikon, CH, November 2007
A. Dommann
"New horizons in Coatingtechnology"
CCMX-Day, Fribourg, CH, March 2007
A. Dommann
"New techniques to determine aging on MEMS"
Panalytical-Meeting, Almelo, NL, November 2007
A. Dommann
"Polymer MEMS for Medical Purposes"
SSB Conference, Neuchatel, CH, May 2007

A. Dommann
"Possible collaboration models in the field of MEMS
with CSEM"
MicroNanoFabrication Annual Meeting, EPFL,
Lausanne, CH, May 2007
A. Dommann
"Reliability for MEMS in Space"
ESTEC, Noordwijk, NL, April 2007
A. Dommann
"Sensors and Nanotech Today"
Mettler-Toledo Wrap-Up 2007, Greifensee, CH,
November 2007
A. Dommann
"X-Ray Analysis on thin films"
EMPA-Conference, Dübendorf, CH, May 2007
M.-A. Dubois, C. Billard, G.Parat, M. Aissi, H. Ziad,
J.-F. Carpentier, K.B. Östman
"Above-IC Integration of BAW Resonators and
Filters for Communication Applications"
Invited paper at 3rd International Symposium on
Acoustic Wave Devices for Future Mobile
Communication Systems, Chiba, JP, March 2007
M.-A. El Mechat
"Realization of multi-3D-TOF camera environments
based on coded-binary sequences modulation "
Optical 3D Measurement Techniques, Zurich, CH,
July 2007
M. El-Khoury, J. Krauss
"International Conference on Portable Information
Devices"
IEEE Portable 2007, Orlando, US, March 2007
C. C. Enz, J. Chabloz, J. Baborowski, C. Muller,
D. Ruffieux
"Building Blocks for an Ultra Low-Power MEMSbased
Radio"
IEEE Int. Workshop on Radio-Frequency
Integration Technology (inveted), Singapore, SG,
December 2007
J. R. Farserotu
"eHealth"
eHealth, Neuchatel, CH, March 2007
J. R. Farserotu
"International Symposium on Medical Information
and Communication Technology 2007"
ISMICT 07, Oulu, FI, December 2007
P. Ferrat, C. Gimkiewicz, S. Neukom, Y. Zha,
A. Brenzikofer, Th. Baechler
"Ultra-miniature camera module with omnidirectional
view for collision avoidance"
Workshop ‘Micro Aerial Vehicles: Design, Control
and Navigation’ at IROS conference, San Diego,
US, November 2007
M. Fretz
"Comsol Conference"
Poster Session, Grenoble, FR, October 2007
P. Glocker
"NEMO-07 Anwenderforum"
Micromontageplattform, Frankfurt a.M., DE,
May 2007
S. Graf, P. Schmid, T. Stöckli, N. Schmid,
H. F. Knapp
"Novel Approach of integrating microrobotics and
microfluidics in cell based assays"
MipTec Poster Session, Basel, CH, May 2007
E. Grenet
"Embedded high dynamic range vision system for
real-time driving assistance"
Sensorik für Fahrerassistenzsysteme, Heilbronn,
DE, September 2007
C. A. Griffiths, S. Bigot, E. Brousseau, M. Heckele,
J. Nestler, J. Auerswald
"4M 2007 Conference on Multi-Material Micro
Manufacture"
Process Characterisation including Process
Chains, Borovets, BG, October 2007
E. Györvary
"The way to Brazil; The different units in Belo; The
aims of CSEM Brasil"
Swiss Innovation Academy, Neuchatel, CH, July
and October 2007
E. Györvary
"Life Sciences at CSEM"
Innovation Day at FIEMG, Belo Horizonte, Minas
Gerais, BR, March 2007
E. Györvary
"Wearable Electronics and Textile Applications"
Textile Seminar ABIT, São Paolo, BR, March 2007
H. Heinzelmann
"CSEM and CSEM Brazil Innovation Center"
Textile Seminar ABIT, São Paolo, BR, March 2007
115

H. Heinzelmann
"CSEM and CSEM Brazil Innovation Center"
Innovation Day at FIEMG, Belo Horizonte, Minas
Gerais, BR, March 2007
H. Heinzelmann
"Nanotechnology meets IEP"
International Executive Program 2007, INSEAD,
Fontainebleau, FR
H. Heinzelmann
"Block Copolymer Lithography"
NordForsk Summer School on Polymer Micro- and
Nano- Fabrication, Palmse, EE, September 2007
H. Heinzelmann
"Research & Project Management"
NordForsk Summer School on Polymer Micro- and
Nano- Fabrication, Palmse, EE, September 2007
H. Heinzelmann
"Engineering for Life Sciences"
Swiss Society of Biomedical Engineering 2007,
Neuchatel, CH, September 2007
H. Heinzelmann
"Micro- and Nano- Tools"
Swiss Innovation Academy, Neuchatel, CH, July
and October 2007
T. Heldal, T. Volden, J. Auerswald, H.F. Knapp
"NSTI Nanotech 2007, 10th Annual
Nanotechnology Conference and Trade Show"
Micro and Nano Fluidics, Santa Clara, US,
May 2007
S. Henein
"7th International Conference of the European
Society for Precision Engineering &
Nanotechnology"
EUSPEN, Bremen, DE, May 2007
K. Hiller, T. Gessner, J. Nestler, J. Gavillet,
S. Getin, E. Quesnel, S. Martin, G. Dellapierre,
J. Soechtig, G. Voirin, L. Buergi, J. Auerswald,
H.F. Knapp, S. Ross, S. Bigot, M. Ehrat, A. Lieb,
M.-C. Beckers, D. Dresse
"Smart Systems Integration Conference"
Special Aspects of Integration, Paris, FR,
March 2007
T. Hinderling
"Le projet Solar Islands"
Energissima, Bulle, CH, June 2007
116
T. Hinderling
"Sensors at CSEM"
SIMTech - Joint Swiss-Singapore Workshop on
Sensors for Harsh Environments, Singapore, SG,
January 2007
A. Hutter
"DAta Systems In Aerospace"
DASIA 2007, Naples, IT, May-June 2007
R. Kern, et al.
"High Throughput Material Testing Apparatus
HTA-7"
ICOE07, Eindhoven, NL, May 2007
G. Kotrotsios
"Environmental monitoring using ultra low power
wireless communication systems"
Greater Nagoya Initiative, Tsu-City. Mie prefecture,
JP, January-February 2007
G. Kotrotsios
"ResearchTransfer to create Business start-ups"
High-level Conference on Nanotechnologies,
Braga, PT, November 2007
R. Krähenbühl, A.-C. Pliska, R. Bauknecht,
S. Aiterrami, A. Peterhans, A. Stump,
K. Krasnopolski, J. Kunde, C. Bosshard
"CTI day in Micro and Nano technologies"
Neuchatel, CH, November 07
Q. Lai, T. Burch, S. Grossmann, A. Stump,
K. Krasnopolski, M. Busse-Grawitz, D. Fengels,
C. Böhler, T. Bragagna, A. Heinrich, S. Gross,
S. Summer, B. Nussbaumer, G. Boer
"CTI Medtech Award 2007 Nominee Presentation"
The LEDDT TM - Platform (Laser Easy Drug Delivery
Technology), a novel injection-free method for
intraepidermal delivery of large molecular weight
drugs., Bern, CH, September 2007
J. Luprano
"New generation of smart sensors for biochemical
and bioelectrical applications"
pHealth-2007, Chalkidiki, GR, June 2007
J. Luprano
"29th Annual International Conference of the IEEE
Engineering in Medicine and Biology Society"
EMBC2007, Lyon, FR, August 2007
J-M. Mayor
"ITER Business Forum"
ITER, Nice, FR, December 2007

A. Meister
"Fluidic nanoprobe patterning"
NaPa Day 2007, Berlin, DE, October 2007
J.-L. Nagel
"Biometric face authentication on mobile devices"
Invited Presentation, Conference on Biometrical
Feature Identification and Analysis, Goettingen,
DE, September 2007
J. Nestler, A. Morschhauser, K. Hiller,
J. Auerswald, H.F. Knapp, T. Otto, T. Gessner
"Smart Systems Integration Conference"
Poster Session, Paris, FR, March 2007
J. Nestler, A. Morschhauser, K. Hiller, S. Bigot,
J. Auerswald, J. Gavillet, T. Otto, T. Gessner
"11th International Conference on Miniaturized
Systems for Chemistry and Life Sciences
(MicroTAS)"
Microfluidics - Aliquoting,Mixing & Pumping, Paris,
FR, October 2007
V. Neuman
"Bio-Innovation Day 2007"
BioInnovationDay07, Lausanne, CH,
November 2007
P. Niedermann
"Comlab as a Tool for Industrial MEMS
Development"
MicroNanoFabrication Annual Review Meeting,
Lausanne, CH, May 2007
E. Onillon
"IEEE/ASME International Conference on
Advanced Intelligent Mechatronics"
AIM 2007, Zurich, CH, September 2007
J. Osmond, G. Isella, D. Chrastina, R. Kaufmann,
H. von Känel
"Ge/Si (100) heterojunction photodiodes fabricated
from material grown by low energy plasma
enhanced chemical vapor deposition"
5th International Conference on Silicon Epitaxy and
Heterostructures (ICSI-5), Marseille, FR, May 2007
S. Pasche, R. Ischer, G. Voirin, M. Liley, J. Luprano
"Wearable biosensors for monitoring wound
healing"
pHealth 2007, Porto-Carras, GR, June 2007
S. Pasche, R. Ischer, G. Voirin
"Biochemical sensors at CSEM"
Proetex Workshop, Gent, BE, September 2007
S. Pasche, R. Ischer, S. Angeloni, M. Liley,
J. Luprano, G. Voirin
"Wearable Biosensors for Health Monitoring"
Biosurf VII – Functional Interfaces for Directing
Biological Response, Zurich, CH, August 2007
A. Perret
"SSI Overview and Perspective – Smart Systems
and Applications"
Euripides Forum, Versailles, FR, June 2007
A. Perret
"HTA General presentation"
SSI Conference, Paris, FR, March 2007
A. Perret
"HTA, Heterogeneous Technology Alliance"
Annual Review Leti, Grenoble, FR, June 2007
A. Perret
"MEMS at CSEM - MEMS Fab Brazil"
Innovation Day at FIEMG, Belo Horizonte, Minas
Gerais, BR, March 2007
A. Perret
"HTA General Presentation"
Smart System Integration Conference, Paris, FR,
March 2007
A. Perret
"MEMS"
Workshop on MEMS, Belo Horizonte, BR,
March 2007
A. Perret
"Micro-nano technology in Western Switzerland"
Development Economique Western Switzerland,
Stuttgart, DE, September 2007
A. Perret
"SSI Overview and Perspective Smart Systems and
Applications"
Euripides Forum, Versailles, FR, June 2007
C. Pickering, M. McNie, C. Reeves, T. Harvey,
T. Ryan, C. Bosshard, H.F. Knapp, G. Schröpfer,
F. von Germar, T. Bauer, P. Janus, P. Gabriec,
C. Moldovan, B. Firtat, A. Richardson
"Smart Systems Integration Conference"
Smart Systems: Design, technologies and
integration, Paris, FR, March 07
C. Piguet
"Awareness Applications and the Related System
Architectures"
Invited Embedded Tutorial at DATE’07, Nice, FR,
April 2007
117

C. Piguet
"High Level Energy and Power Reduction
Strategies"
Invited Talk at CLEAN Workshop, Munich, DE,
September 2007
C. Piguet
"Histoire des microprocesseurs horlogers"
FTFC Journées Faible Tension Faible
Consommation, Paris, FR, May 2007
C. Piguet
"La conception de SoC pour des réseaux de
capteurs"
FETCH 2007, Villard de Lans, FR, January 2007
C. Piguet
"Low Power Design in Deep Submicron 65 & 45 nm
Technologies"
ICECS’07, Marakesh, MA, December 2007
C. Piguet
"Total Energy and Total Power Reduction at
Architectural Level"
Invited Talk at CLEAN Workshop, Stresa, IT,
March 2007
A.-C. Pliska, R. Bauknecht, R. Krähenbühl,
A. Peterhans, A. Stump, S. Aiterrami, C. Bosshard,
J. Kunde
"Smart Systems Integration Conference"
Microsystems Packaging and System Integration,
Paris, FR, March 07
A.-M. Popa, J. Polesel Maris, R. Pugin,
H. Heinzelmann
"Force spectroscopy in liquid media - an AFM study
of nanostructured surfaces functionalized with
responsive molecules"
SAOG, Fribourg, CH, January 2008
A.-M. Popa, J. Polesel Maris, R. Pugin,
H. Heinzelmann
"AFM characterisation of responsive
nanostructured surfaces"
Joint workshop of the Marie Curie Research and
Training Networks POLYAMPHI and
BIOPOLYSURF and the ESF EUROCORES
project BIOSONS, Biarritz, FR, February 2008
R. Pugin
"Nanotechnology and Textiles"
Textile Seminar ABIT, São Paolo, BR, March 2007
R. Pugin
"Nanotechnology at CSEM"
Innovation Day at FIEMG, Belo Horizonte, Minas
Gerais, BR, March 2007
118
M. Ramuz, et al.
"Patterning of polymer light-emitting devices by a
printing method "
Workshop “Innovations in Inkjet Polymers for
Biomaterials and Nanoparticles”, Eindhoven, NL,
June 2007
J. Rousselot
"12th IEEE Symposium on Computers and
Communications "
ICC 2007, Aveiro, PT, July 2007
J. Rousselot
"European Ultra Wide Band Radio Technology
Workshop"
UWB 2007, Grenoble, FR, May 2007
A. S. Roy, C. C. Enz
"A Charge-Based Compact Flicker Noise Model
Including Short-channel Effects"
NSTI Nanotech - Workshop on Compact Modeling
(WCM 2007), Santa Clara, US, May 2007
A. S. Roy, C. C. Enz, J.-M. Sallese
"Theory of Source-Drain Partitioning in MOSFET"
NSTI Nanotech - Workshop on Compact Modeling
(WCM 2007), Santa Clara, US, May 2007
A. S. Roy, C. C. Enz
"An Analytical Thermal Noise Model of DG
MOSFET and Comparison with Bulk MOSFET"
Int. Conf. on Noise and Fluctuations (ICNF), Tokyo,
JP, September 2007
A. S. Roy, C. C. Enz
"Analytical Noise Modeling in MOSFET"
Int. Conf. on Noise and Fluctuations (ICNF, Tokyo,
JP, September 2007
P.-F. Rüedi, E. Grenet, F. Lustenberger
"Battery powered high dynamic range vision
system"
ISCAS, New Orleans, US, May 2007
P.-F. Rüedi
"High dynamic range vision sensor for embedded
applications"
Workshop on Image sensors analog and digital onchip
processing, Toulouse, FR, November 2007
P.-F. Rüedi
"High dynamic range vision sensor for embedded
applications"
Image sensor analog and digital on-chip
processing, Toulouse, FR, November 2007

E. Scolan, V. Monnier, R. Pugin
"Nanostructured sol-gel surfaces"
Colloque Solgel 2007, Tours, FR, February 2007
E. Scolan, V. Monnier, R. Pugin
"Nanostructured sol-gel surfaces"
International Sol-Gel Workshop 2007, Montpellier,
FR, September 2007
P. Seitz, S. Beer, Y. Delley
"Smart pixel array for the simultaneous detection of
phase and amplitude envelope, enabling real-time
nanometer-precision OCT"
Frontiers of Electronic Imaging, World of
Photonics 2007, Munich, DE, June 2007
P. Seitz
"Business Value Creation – The CSEM Innovation
Center Model"
ETH Project Presentations for the Official
Singapore Delegation, Zurich, CH, October 2007
P. Seitz
"Change Management"
Swiss Innovation Academy, Neuchatel, CH,
September 2007
P. Seitz
"Creativity"
Swiss Innovation Academy, Neuchatel, CH,
July 2007
P. Seitz
"Das CSEM Forschungszentrum für Nanomedizin
in Landquart"
Unternehmertreff im Alpenrheintal, Maienfeld, CH,
June 2007
P. Seitz
"Didactics, Presentations and Publications"
Swiss Innovation Academy, Neuchatel, CH,
July 2007
P. Seitz
"Europhot – The European Initiative for Single-
Photon Electronic Imaging"
Europhot Presentation, Unit Head Photonics,
Bruxelles, BE, February 2007
P. Seitz
"Lab-on-a-Chip Using Organic Semiconductors"
4th Optoelectronic and Photonic Winter School on
Biophotonics, Trento, IT, March 2007
P. Seitz
"Lab-on-a-Chip Using Organic Semiconductors"
Swiss Innovation Academy, Neuchatel, CH,
July 2007
P. Seitz
"Moderne Halbleiter-Bildsensorik"
Intensive industrial training course, Hamburg, DE,
July 2007
P. Seitz
"Nanomedicine in Europe and in Switzerland"
Biomedical Workshop, Inselspital, Bern, CH,
February 2007
P. Seitz
"Nanomedizin – Wissenschaftsgebiet mit enormem
Zukunftspotential"
CSEM Innovation Day, Zurich, CH, November 2007
P. Seitz
"Optical Biochips"
4th Optoelectronic and Photonic Winter School on
Biophotonics, Trento, IT, March 2007
P. Seitz
"Optical Biochips – Basics"
Swiss Innovation Academy, Neuchatel, CH,
July 2007
P. Seitz
"Photon-Noise Limited Distance Resolution of
Optical Metrology Methods"
SPIE Conference on Optical Metrology, Munich,
DE, June 2007
P. Seitz
"The Art of Happiness at Work"
Swiss Innovation Academy, Neuchatel, CH,
September 2007
P. Seitz
"The Grand Challenges of Photonics (General
Chair and Moderator)"
EOS Conference on Photonics, World of
Photonics 2007, Munich, DE, June 2007
P. Seitz
"The history of optical time-of-flight techniques for
3D imaging "
Frontiers of Electronic Imaging, World of
Photonics 2007, Munich, DE, June 2007
P. Seitz
"Tiens, vous voulez faire une carrière scientifique"
Atelier du Laboratoire Européen Associé en
Microtechnique, Arc-et-Senans, FR,
September 2007
J. Solà I Caros
"4th International Workshop on Wearable and
Implantable Body Sensor Networks"
BSN 07, Aachen, DE, March 2007
119

J. Solà I Caros
"Annual meeting of the Swiss Society of Biomedical
Engineering"
SSBE 2007, Neuchatel, CH, September 2007
R. P. Stanley
Workshop on Photonic Crystals, Prague, CZ,
April 2007
R. Steiger
"New devices based on nanoparticulate,
mesoporous metal oxide coatings"
International Conference on Nanotechnology and
Advanced Materials, Hong Kong, CN,
December 2007
G. Suarez, S. Pasche, G. Voirin, Y. Leterrier,
A. Sayah
"Lab-On-Chip for Analysis and Diagnostics"
CCMX First Annual Meeting, Fribourg, CH,
March 2007
R. Vetter
"9th Meeting of the European Federation of
Autonomic Societies 18th Meeting of the American
Autonomic Society 2nd Joint Meeting EFAS - AAS"
EFAS 2007, Vienne, AT, October 2007
G. Voirin, R. Ischer, M. Ramuz, L. Bürgi,
R. P. Stanley, D. Leuenberger, J. Söchtig,
C. Winnewisser
"SEMOFS: Micro-Optical Platform for Plasmon
Sensing"
SEMOFS Workshop, Borovets, BG, October 2007
G. Voirin, J. Söchtig, L. Buergi, R. P. Stanley,
S. Getin, E. Quesnel, B. Fillon, J. Gavillet, S. Bigot,
M. Ehrat, A. Lieb
"m-Optics technologies"
SEMOFS Workshop, Borovets, BG, October 2007
120
G. Voirin, G. Dudnik, J. Luprano
"Advanced e-textiles for firefighter and civilian
victims"
3rd Global Plastic Electronics Conference &
Showcase, Plastic Electronics Foundation, DE,
October 2007
B. Wenger, M.-H. Song, N Tétreault, R. H. Friend
"Tunability of flexible polymer distributed feedback
lasers"
International Symposium on Ultrafast- and Nano-
Optics, Beijing, CN, October 2007
C. Winnewisser
"Integrated Optoelectronic Systems based on
Solution Processed Polymeric Semiconductor
Materials"
NanoEurope 2007, St. Gallen, CH,
September 2007
C. Winnewisser
"Towards Integrated Photonic Systems based on
organic Semiconductor Materials"
Plastic Electronics 2007, Frankfurt, DE,
October 2007
Q. Xu, J. R. Farserotu, J. Ayadi, J. F. M. Gerrits
"18th Annual IEEE International Symposium, on
Personal, Indoor and Mobile Radio
Communications"
IEEE PIMRC’07, Athens, GR, September 2007
H. Zhan
"10th International Symposium on Wireless
Personal Multimedia Communications"
WPMC 07, Jaipur, IN, December 2007

Competence Centre for Materials Science and Technology (CCMX) and National Center
of Competence in Research (NCCR) Projects
CCMX-MMNS Lab-on-a-chip for Analysis and Diagnostics
NCCR Module 5 – Functional Materials by Hierarchical Self-Assembly (proposal for last financing round)
Swiss Commission for Technology and Innovation (CTI)
8704.1 NMPP-NM ALDEBARAN A low-power 2.4 GHz CMOS radio transceiver IC for the Wibree
standard
8035.2 ARGUS Hochintegrierter 1.3 Mpixel Bildsensor mit hoher optischer Sensitivität
für eine Hochgeschwindigkeits-Kameraanwendung
8759.1 EPRP-IW COATING ENGINEERING Engineering of thin film crystallinity of wear resistant coatings using a
combination of PECVD and PVD plasma technology
7796.1 DIXI Digital Phase Contrast Imaging for Medical DiagnosticsOK
8272.1 NMPP-NM DMS Digital motion sensor
8039.2 NMPP-NM DOSENS II Development of a new dissolved oxygen sensor for activated sludge
monitoring based on a membrane-less, self-calibrating, self-cleaning
microdisk array sensing electrode
8627.2 El PICA Custom designed organic electroluminescent pictograms for
pushbutton applications
9032.1 PFIW-IW FMM Feeding Module for Microfactory
8227.1 HELIOCT Entwicklung einer neuartigen Mikroskopie-Technologie zur 3D
Bildgebung in Echtzeit
8247.2 LSPP-LS IOS iOS– Development of an implant to place on the bones of people
touched by the Parkinson disease in order to decrease the symptoms
8018.2 LSPP-LS LASETIME The LEDDT – Platform (Laser Easy Drug Delivery Technology), a
novel injection-free method for intraepidermal delivery of large
molecular weight drugs.
7963.1 LONGLITE Aging mechanisms and numerical device physics of organic LEDs
7482.2 MEMSORS Micro-machined Electrostatic Sensors for acoustic Sensors
8452.1 NMPP-NM MICROS Entwicklung eines neuartigen miniaturisierten Linearencoders
optimiert für den Einsatz mit lasergeschriebenen Massstäben
8325.1 NIMROD Nicht-invasive Messung der Retina ohne Dilatation
8648.1 PERTEST Pre-Employment and Rehabilitation Tester
7474.2 NMPP-NM POLITE New electroluminescent polymers for large area lighting applications
8037.2 NMPP-NM POWERPACK Low-cost packages for ultrabright light sources
9146.2 PFIW-IW PTMR Pseudo Tactile Microassembly Robotics
9119.1 ROVARP Rotationsvariable Farbpigmente
8621.2 SCL ll Smart Compliance Labels
121

8241.2 DCPP-NM SOLID Solid on Liquid Deposition
8817.1 NMPP-NM VENUS An integrated radio solution for ultra low-power wireless wristwatches,
automotive remote-controls, and wireless sensor network
applications
7843.2 NMPP-NM WOME Study and conception of a low power, reconfigurable OFDM modem
for multimode wireless broadband communications. WOME : Wireless
OFDM Multimode Engine
7804.1 XCAN Röntgen-Detektoren mit Einzelphoton-Detektion
European Community Projects
FP6 – NMP µSAPIENT Synergetic Process Integration for Efficient Micro and Nano
Manufacture
FP6 – IST ARTTS Action Recognition and Tracking based on Time-of-flight Sensors
FP6 – IST MOBILITY BIOPOLYSURF Engineering advanced polymeric surfaces for smart systems in
biomedicine, biology, material science and nanotechnology: A
crossdisciplinary approach of biology, chemistry and physics
FP6 – IST NMP BIOTEX Bio-sensing Textile for Health Management
FP6 – SUSTDEV HOLISTIC Holistic Optimisation Leading to Integration of Sustainable
Technologies in Communities
FP6 – IST CRUISE CReating Ubiquitous Intelligent Sensing Environments
FP6 – NMP DIPNA Development of an Integrated Platform for Nanoparticle Analysis to
verify their possible toxicity & the eco-toxicity
FP6 – INFRASTRUCTURES EARLINET-ASOS European Aerosol Research Lidar Network: Advanced Sustainable
Observation System
FP6 – IST e-SENSE Capturing Ambient Intelligence for Mobile Communications through
Wireless Sensor Networks
FP6 – IST GOODFOOD Food Safety and Quality Monitoring with Microsystems
FP6 – NMP HYDROMEL Hybrid Ultra-Precision Manufacturing Process Based on Positional-
and Self-assembly for Complex Micro-Products
FP6 – NEST IDEA Imaging device for electrophysiological activity monitoring of neuronal
cell cultures
FP6 – IST INTEGRAMplus Integrated MNT Platforms & Services
Interreg LEA LEA-2006-2007 Laboratoire Européen Associé pour la formation et le transfert de la
technologie dans le domaine de la Microtechnique
FP6 – IST MAGNET BEYOND My personal Adaptive Global Network Beyond
FP6 – SME MAP2 Micro-Architectural Power management: Methods, Algorithms and
Prototype tools
FP6 – NMP MEDITRANS Targeted delivery of nanomedicine
COST MIE-OPIC Mie Resonances in Opal Photonic Crystals
FP6 – IST MINAMI Micro-Nano integrated platform for transverse Ambient Intelligence
applications
122

FP6 – INFRASTRUCTURES MNT Europe Staircase towards European MNT Infrastructure Integration
FP6 – IST MUFLY Fully Autonomous Micro Helicopter
FP6 – IST NANOHAND Micro-nano System for Automatic Handling of Nano-objects
FP6 – NMP NANOSAFE2 Safe production and use of nanomaterials
FP6 – NMP NANOSECURE Advanced nanotechnological detection and detoxification of harmful
airborne substances for improved public security
FP6 – NMP NAPA Emerging nanopatterning method
FP6 – NMP NAPOLYDE Nano-structured polymer deposition processes for mass production of
innovative systems for energy production & control and for smart
devices
FP6 – IST NEMO EU Network of Excellence: Micro-Optics
FP6 – NMP NEWBONE Development of load-bearing fibre reinforced composite based
nonmetallic biomimetic bone implant
FP6 – INFRASTRUCTURES OPTICON Optical Infrared Coordination Network for Astronomy
FP6 – IST Phodye New Photonic systems on a chip based on dyes for sensor
applications scalable at wafer fabrication
FP6 – IST PLASMO-NANO-DEVICES Surface plasmon nanodevices – Towards sub-wavelength
miniaturization of optical interconnections and photonic components
FP6 – IST PLEAS Plasmon Enhanced Photonics
FP6 – IST PROETEX Protection e-Textiles: MicroNanoStructured fibre systems for
Emergency- Disaster Wear
FP6 – IST PULSERS Pervasive Ultrawideband Low Spectral Energy Radio Systems
FP6 – IST ROLLED Roll-to-roll manufacturing technology for flexible OLED devices and
arbitrary size and shape displays
FP6 – IST SCIER Sensor and Computing Infrastructure for Environmental Risks
FP6 – SUSTDEV SCOUT-O3 Stratospheric-climate links with emphasis on the UTLS (SCOUT-O3)-
EC 505390-GOCE-CT-2004
FP6 – IST NMP SEMOFS Surface enhanced micro optical fluidic systems
FP6 – IST NMP SMARTHEALTH Smart Integrated Biodiagnostic Systems for Healthcare
FP6 – IST WASP Wirelessly Accessible Sensor Populations
FP6 – AEROSPACE WISE Integrated wireless sensing
European Space Agency (ESA), European Southern Observatory (ESO) and
Astrophysical Instrument Projects
ESA Projects
GSTP Laser Diode caracterisation at 779 nm (ESA Technological Program GSTP-4)
LIDAR PRN Development of Pseudo-Random Noise continuous-wave Lidar Prototype (ESA Technological Program
GSTP-4)
123

LISA-PAAM Development, demonstration manufacturing and test of a closed loop controlled, pico-radians resolution, tiltmirror,
as “Point Ahead Angle Mechanism” for the ESA LISA-LPT
LTMS-2 Long Term Medical Survey system ground prototype
OSCAR Ultrastable Atomic Beam Clock for Telecom Space Applications and Long-Term Space Missions (ESA
Technological Program ARTES-5)
OSCC Development of an Optically Pumped Space Cesium Clock (ESA Technological Program ARTES-5)
SHM Development of Space Hydrogen Maser for ACES
SPHERE Reaction sphere for attitude control
SPHM Design Consolidation, Industrialisation and Lifetime Qualification of a Physics Package for a Passive
Hydrogen Maser (PHM) (Galileo System Test Bed – Version 2, GSTB-V2)
ESO Projects
ELT-M5-FSU Development, demonstrator manufacturing and test of a Field Stabilisation Unit (FSU) for the M5 mirror on
the future ELT (Extremely Large Telescope, 40 m) of ESO
PRIMA-DDL Systems engineering for the development, manufacturing, test and integration of a Differential Delay Line
(DDL) for the PRIMA instrument of the ESO-VLT (Very Large Telescope) interferometer line at Cerro
Paranal, Chile
Astrophysics Projects
EMIR-DTU Development, manufacturing and test of a Detector Translation Unit (DTU) for the EMIR instrument on the
Gran Canaries Telescope (GTC) of Spain (IAC, Instituto de Astrofisica de Canaries)
MOSFIRE CSU Development, manufacturing, test and integration of a Configurable Slit mask Unit for the Multi-Object
Spectrometer for Infra-Red Exploration Instrument (MOSFIRE) to be mounted on the W.M. Keck Observatory
Telescope, Hawaii USA
Industrial Property
Creativity
In 2007, 34 invention reports were submitted for examination.
Patent portfolio
CSEM inventions have led to 23 patent applications in 2007 (13 regular applications and 10 US provisional applications). The patent
portfolio has been further enhanced by the extension of different countries of 21 patent files based on prior patent applications.
Collaboration with Research Institutes and Universities
University Institute Professor Field of collaboration
CEA LETI J.-R. Lequepeys Leakage reduction, processor
EPF Lausanne Advanced Photonics Laboratory R. Salathé Biochemical Nanofactory
EPF Lausanne CMI Center of MicroNanotechnology C. Hibert Etching and nanofabrication
EPF Lausanne CSI G. De Micheli CCMX leakage reduction
EPF Lausanne Institut de chimie physique H. Vogel Fluorescent Nanoparticles
EPF Lausanne Laboratoire de microsystèmes 2 M. Gijs Lab-On-A-Chip
EPF Lausanne Laboratory for regenerative medicine
and pharmacobiology
124
J. Hubbell Generic scavenger powered DSPbased
SoC for emerging implantable
biosensors and bioactuators
EPF Lausanne LAP P. Ienne Processor

University Institute Professor Field of collaboration
EPF Lausanne LEG M. Declercq Medical, processor
EPF Lausanne LPM2 P. Ryser Medical, processor
EPF Lausanne LSM Y. Leblebici CCMX leakage reduction
EPF Lausanne Nanoengineering J. Brugger Nanoscale structuring,
nanofabrication
EPF Lausanne Nanostructuring Research Group P. Hoffmann Block copolymer self-assembly.
Design of templated and chemically
modified surfaces
EPF Lausanne STI-LMIS 4 P. Renaud Superparamagnetic Nanoparticles
EPF Lausanne STI-IMX-Ceramics P. Muralt Sensors
EPF Lausanne STI-IMX-LTP H. Hofmann Ceramics
ETH Zurich BioInterfaceGroup M. Textor Parylene
ETH Zurich Department of electrical engineering J. Vörös AFM on cells
ETH Zurich Department of materials H. Hall-Bozic Biomaterials
ETH Zurich Institut für Atmosphäre und Klima T. Peter Lidar Measurements from Highaltitude
aircraft
ETH Zurich Institute of Mechanical Systems E. Mazza Reliability of Silicon MEMS
ETH Zurich Laboratorium für Organische Chemie F. Diederich Dendrimer self-assembly
ETH Zurich Laboratory for Surface Science and
Technology
N.D. Spencer,
M. Textor
Polymer nanostructuration
ETH Zurich Nanotechnology Group A. Stemmer Automated Cell Injection
HE – ARC Microtechnique H. Keppner Parylene
TU Berlin / IZM Berlin Micro Materials Centers Berlin B. Michel Reliability of Silicon MEMS
Uni Ulm Institut für Mikro- und Nanomaterialien H. Fecht Reliability of MEMS
University Hospital
Zurich
University Hospital
Zurich
University Hospital
Zurich
Neonatology M. Wolf Near infrared spectroscopy
Nuclear Medicine B. Weber Brain imaging and OCT
Nuclear Medicine A. Buck Fluorescent Probes
University of Mulhouse Institut de Chimie des surfaces et
interfaces ICSI
University of Neuchatel IMT A. Neels,
H. Stoeckli-Evans
G. Reiter Polymers self-assembly
Crystallography
University of Neuchatel IMT H.-P. Herzig Packaging
University of Neuchatel IMT N. F. de Rooij MEMS
University of Neuchatel IMT N. F. de Rooij Digital motion sensor
125

University Institute Professor Field of collaboration
University of Neuchatel IMT P.-A. Farine Leakage reduction
University of Neuchatel IMT, SAMLAB M. Koudelka-Hep Micro-electrode arrays
University of Neuchatel Institut d’Hydrogéologie E. Verrecchia NP screening by mass spectroscopy
University of Neuchatel Institut de Microtechnique T. Bürgi Surface chemistry characterization by
IR based spectroscopy
University of Neuchatel Institut de Zoologie (Parasitologie) B. Betschart Cell biology
University of Ulm Inorganic Chemistry I N. Hüsing Mesoporous sol-gel thin films
Vienna University of
Technology
Vienna University of
Technology
126
Applied inorganic chemistry group of
the institute of material chemistry
U. Schubert Sol-gel processes
Institute of Materials Chemistry U. Schubert Metallic nanoparticles doped
nonporous layers
ZHW CCP H. Schwarzenbach PLEDs
Teaching
Title of lecture Context Location
J. Auerswald Werkstoffe der Elektrotechnik Werkstoffkunde Vorlesung HSLU T&A, Luzern
N. Blanc
C. Bosshard
Méthodes de détection optique Institut de Microélectronique et
Microsystèmes
Photo & Machine Vision Institute of Geodesy and
Photogrammetry
EPF Lausanne
ETH Zurich
Assembly and Packaging Swiss Innovation Academy CSEM Alpnach
Nonlinear Optics ETH Zurich Zurich
(Non)linear Optical Spectroscopy:
Basics and Applications
ETH Zurich Zurich
L. Bürgi Organic Optoelectronics Swiss Foundation for Research and
Microtechnology (FSRM)
Summerschool “Highlights in
Microtechnology" 2005
E. Charbon
and P. Seitz
A. Dommann
Modern solid-state image sensing Master Program in Electrical
Engineering
Aging measurements on
microstructures
Neuchatel
EPF Lausanne
BeNeFri - HRXRD Workshop CSEM Neuchatel
MEMS technologies Swiss Innovation Academay CSEM Neuchatel
Coating Technologies Universitärer MNT-Master Dornbirn
Coating Technologies and X-Ray
Analysis
High Resolution X-Ray Diffraction on
thin films
MNT-Masterstudiengang Dübendorf
CCMX-PhD Seminar Luzern
C. C. Enz Advanced Analog and RF IC Design I Master in Microelectronics EPF Lausanne

C. C. Enz
J. R. Farserotu
Title of lecture Context Location
Advanced Analog and RF IC Design II Master in Microelectronics EPF Lausanne
MOS Transistor Modeling for Low-
Voltage and Low-Power Circuit Design
Trade-offs in Designing LP-LV RF
Transceivers in Standard Digital
CMOS
MOS Transistor Modeling in Deep
Submicron
MOS Transistor Modeling for RF IC
Design
Low-Frequency Noise Reduction
Techniques
Low-Voltage, Low-Power Analog
CMOS IC Design
Low-Voltage, Low-Power Analog
CMOS IC Design
EPF Lausanne
EPF Lausanne
Practical Aspects in Mixed-Mode ICs EPF Lausanne
RF Analog IC Design EPF Lausanne
Low-Noise, Low-Offset Analog IC
Design
High-Frequency Noise Low-Noise, Low-Offset Analog IC
Design
Satellite Communication System and
Networks
Executive Master in eGovernance,
eGov
chargé de cours, systèmes de
communication and Space Technology
Eservices from the sky and satellite
systems 18 July 2007
EPF Lausanne
EPF Lausanne
EPF Lausanne
EPF Lausanne
RF signals and test 18 April 2007 FSRM, Neuchatel
E. Györvary The way to Brazil – The different units
in Belo Horizonte – The aims of CSEM
Brazil
H. Heinzelmann
S. Henein
Swiss Innovation Academy CSEM Neuchatel
Micro-and Nano Tools Swiss Innovation Academy CSEM Neuchatel
Research & Project Management NordForsk Summer School on
Polymer Micro- and Nano- Fabrication
Block Copolymer Lithography NordForsk Summer School on
Polymer Micro- and Nano- Fabrication
Construction (Precision Machine
Design)
Composants Microtechnques
(Microtechnoloy Components)
Flexure-based Mechanisms for High
Precision
Students in Microtechnology, 1st year
(2 hours/week)
Students in Microtechnology, 2nd and
3rd year (4 hours/week)
4 hours Tutorial in the frame of the 7th
International Conference of the
European Society for Precision
Engineering & Nanotechnology
Tallinn, Estonia
Tallinn, Estonia
Bern University of
Applied Science
Bern University of
Applied Science
Bremen, Germany
Conception des guidages flexibles Formation continue FSRM, Neuchatel
H. F. Knapp Microfluidics Swiss Innovation Academy Lecture CSEM Neuchatel
M. Liley
AFM for Life Sciences Swiss Innovation Academy CSEM Neuchatel
AFM for Life Sciences Summer School Highlights in
Microtechnology
Neuchatel
127

128
Title of lecture Context Location
R&D with Industry: what makes a good
project
3rd BioPolySurf Summer School Ovronnaz
M. Liley Nanotoxicology Masters in nanotechnology University of Neuchatel
A. Meister
P. Niedermann
Fluidic nanopatterning Doctoral course MEMS and
nanotechnology
Nanoscale dispensing of ultrasmall
droplets
Nanoscale dispensing of ultrasmall
single droplets
EPF Lausanne
3rd BioPolySurf Summer School Ovronnaz
PANAMA summer school Toulouse, France
Project presentation Swiss Innovation Academy CSEM Neuchatel
Process definition and realisation Swiss Innovation Academy CSEM Neuchatel
T. Overstolz Optical Switch Characterization Swiss Innovation Academy CSEM Neuchatel
C. Piguet
Design for Leakage Reduction Advanced CMOS IC Design EPF Lausanne
Microélectronique pour Systèmes sur
Chips
Evolution de la microélectronique et
SoC
EPF Lausanne
HES-SO EIF
Microelectronic Technology ALaRI Course on Embedded Systems University of Lugano
Ultra-Low Power Circuit Design University of Neuchatel
Digital IC and SoC Design University of Neuchatel
A.-C. Pliska Integration in Microelectronics
Packaging
E. Scolan Sol-gel made nanoporous layers for
sensing applications
P. Seitz
Swiss Innovation Academy CSEM Alpnach
EU-project NAPOLYDE Midterm
workshop
Entrepreneurship Master Program in Micro and Nano
Sciences
Solid-state image sensors Master Program in Micro and Nano
Sciences
Management des Projets R&D Bachelor Program in Micro and Nano
Sciences
G. Spinola IC Package Design & Reliability with
CAE
C. Urban
CEA, Grenoble, France
University of Neuchatel
University of Neuchatel
University of Neuchatel
Swiss Innovation Academy CSEM Alpnach
Méthodes de détection optique Institut de Microélectronique et
Microsystèmes
Photo & Machine Vision Institute of Geodesy and
Photogrammetry
EPF Lausanne
ETH Zurich
M. Wannemacher Informationssysteme Bachelor Course HSLU T&A, Luzern

Title of lecture Context Location
C. Winnewisser Polymer Optoelectronic Technologies
and their Applications
One day workshop within Swiss
Foundation for Research and
Microtechnology (FSRM) Course
Series
R. Wyss Digitale Signalverarbeitung FH Course HSLU T&A, Luzern
Theses
PhD Degrees Awarded in 2007
Name University Title
C. Schuster University of Neuchatel Leakage aware digital design optimization for minimal total power
consumption in nanometer CMOS technologies
CSEM Employees carrying out a PhD
Name Professor / University Theme / CSEM Unit Start year
K. Ali P. Fua / EPF Lausanne Training embedded vision systems / Microelectronics 2007
Zurich
B. Banerjee C.C. Enz / EPF Lausanne Reconfigurable baseband architecture for digital radio
/ Microelectronics
J. Chabloz C.C. Enz / EPF Lausanne Low power receiver using RF-MEMS -analog IC design
/ Microelectronics
M. Contaldo C.C. Enz / EPF Lausanne Low-Power MEMS based CMOS Radio Transmitter
Architectures / Microelectronics
L. Davoine H.-P. Herzig / University of Neuchatel Organic Coupled Subwavelength Devices / Photonics 2007
M’H. El Mechat H.-A. Loeliger / ETH Zurich Examination of modern modulation schemes for future
3D-TOF cameras / Photonics
M. Fretz H.-P. Herzig / University of Neuchatel Flip-chip bond technologies for System-in-Packages
/ Microrobotics
S. Graf A. Stemmer / ETH Zurich Automated cell injection system / Microrobotics 2007
M. Guillaumée B. Deveaud-Plédrand / EPF Lausanne Surface plasmons / Nanotechnology & Life Sciences 2006
B. Kheradman C. Piguet / CSEM
Y. Leblebici / EPFL
Process variations and leakage current in digital circuits
/ Microelectronics
M. Klein J. Brugger / EPF Lausanne Polymer templated nanopatterning for MEMS
applications / Nanotechnology & Life Sciences
R. Lockhart P. Renaud / EPF Lausanne MEMS programmable diffraction gratings
/ Nanotechnology & Life Sciences
V. Longchamp F. Mondada / EPF Lausanne
A. Martinoli / EPF Lausanne
Planatary visual exploration with a team of mobil robots
/ Microrobotics
A.-M. Popa J.A. Hubbell / EPF Lausanne Design, characterization and applications of stimuli
responsive surfaces based on macromolecules
/ Nanotechnology & Life Sciences
J. Nüesch P. Seitz / University of Neuchatel Element-sensitive X-ray microscopy and micro-
Computer-Tomography / Nanomedicine
129
2007
2003
2006
2006
2005
2007
2007
2006
2006
2005
2007

Name Professor / University Theme / CSEM Unit Start year
J. Przybylska P. Renaud / EPF Lausanne Nanodispensing of liquids in attoliter scale using probe
arrays / Nanotechnology & Life Sciences
M. Ramuz P. Seitz / University of Neuchatel High-efficiency photodetectors with organic
semiconductors / Photonics
F. N. Reale M. Vetterli / EPF Lausanne Voice restoration system for laryngectomees
/ Systems Engineering
J. Rousselot J.-D. Decotignie / EPF Lausanne Energy Efficient Routing for Wireless Sensor Networks
/ Systems Engineering
A. Schifferle E. Mazza / ETH Zurich Fracture behavior of single crystal structures
/ Microtechnology and MEMS
O. Schleusing J.-M. Vesin / EPF Lausanne Voice restoration of distorted speech due to
laryngectomy / Systems Engineering
J. Solà I Caros R. Müller / ETH Zurich Continuous non-invasive blood pressure estimation
/ Systems Engineering
J. Taprogge B. Nelson / ETH Zurich High speed CAD model tracking for microassembly tasks
/ Microrobotics
L. Wang P. Hoffmann / EPF Lausanne Nanopatterning by block copolymer lithography
/ Nanotechnology & Life Sciences
G. Weder J. Vörös / ETH Zurich Interaction of cells with nano-patterned surfaces
/ Nanotechnology & Life Sciences
H. Zhan J.-Y. Le Boudec / EPF Lausanne Impulse Radio Ultra-Wideband Channel Estimation and
Location Technology / Systems Engineering
Commissions and Committees
N. Blanc Board member, Swiss Society for Sensor Technology
C. Bosshard Advisory Board of Advanced Functional Materials
Board member of the SwissLaser Net
A. Dommann Board ESM
Board member, Swiss Vacuum Society
Committee member CCMX: ERU: Particle and coatings (SPERU)
Excom member NanoTera
Member of CTI-MNT group
Member of technical committee of ENIAC
Member of the expert team of BMFIT, Vienna
Member of the selection board ESA, Noordwijk
Member of the steering board of EUCEMAN
President of Swiss MNT Network
C. C. Enz Member of the Technical Program Committee of the International Solid-State Circuits Conference
(ISSCC 2007), San Fransisco, USA
Technical Program Committee, European Solid-State Circuits Conference (ESSCIRC 2007), Paper
Selection Meeting, Meeting of the ESSCIRC-ESSDERC Steering Committee, Munich, DE, 2007
130
2007
2006
2006
2005
2006
2007
2004
2006
2007
2006
2007

J. R. Farserotu Member of the Editorial Board of Wireless Personal Communications An International Journal,
Springer
Vice-Chair and Research Co-ordinator, Hermes Partnership, a network of leading organizations in
wireless and mobile communication in Europe
Vice-Chair, European Telecommunication Standards Institute (ETSI), ETSI Project eHealth (EP
eHealth)
H. Heinzelmann Evaluator for ERC Starting Grants
Expert for Austrian Nano initiative
International Advisory Board, Nanomedicine WIRE
International Scientific Committee Smart System Integration, Paris, France
Member of German Physical Society (DPG)
Member of SPG
PhD Committee, V. Spassov
Program Committee MNE 2007, Copenhaguen, Denmark
Program Committee SPP3, Dijon, France
Science Advisory Board, Nanodimension
Secretary Nanotechnology, Swiss Society for Optics and Microscopy
T. Hinderling Member of Steering Committee Nano-tera
Member of Steering Committee of CCMX
Member of Steering Committee of NCCR Quantum Photonics
G. Kotrotsios Member of Organizing Committee, Industrial Liaison, SSBE Annual Meeting 2007, Neuchatel,
Switzerland
Member of Scientific Committee 4th Phealth Conference, Porto Carras, Chalkidiki, Greece
Member of the International Committee, 29th Annual International Conference of the IEEE
Engineering in Medicine and Biology Society in conjunction with the Biennial Conference of the
French Society of Biological and Medical Engineering, August 2007, Lyon, France
A. Perret ANR, Agence Nationale pour la recherche (FR), Project reviewer
ASRH Scientific Board
BioAlps Board
Conseiller personnel du chef de la division Recherche et Technologie du CEA (FR)
EpoSS Communalities Group
Euripides Scientific Adviser of the Board, Council Member and Adviser of the Council
Groupe d’experts : vision stratégique de la nouvelle école issue de la fusion de l'Ecole d'ingénieurs
de Genève et de l'Ecole d'ingénieurs de Lullier
Heterogeneous Technology Alliance, Steering Committee Coordinator
Holst Center Eindhoven, Advisory Board Member
Président du Comité scientifique et technologique de la Fondation Franco-Suisse pour la
Recherche et la Technologie (FFSRT)
Program Committee of Smart System Integration Conference
Secrétaire de la Fondation du prix Omega
131

C. Piguet Member of the Board of the Strategic Research Foundation of Sweden (SSF). STRINGENT
Project, Linköping University
Membre de l’Editorial Board of Microelectronics Journal, Elsevier
Membre du comité de rédaction du bulletin de la Société Suisse de Chronométrie
Membre du Conseil d’Administration de Centredoc, Neuchatel
Program Committee and Special Session Organizer at ICECS 2007, ICECS’07
Program Committee of DASIP 2007 MINATEC
Program Committee of ESSCIRC 2007
Special Sessions Chair DATE 2007, Nice
Steering and Program Committee of FTFC’07
Steering and Program Committee of Low-Power Symposium ISLPED’07
Steering and Program Committee PATMOS'07
Steering Committee of the ALaRI Master Course, University of Lugano
P. Seitz Chairman of the board of Dynetix AG, CH-Landquart
Chairman of the board of Heliotis AG, CH-Root
Delegate of the EOS board for European Affairs, D-Hannover
Editor-in-Chief, Sensors Scientific Journal
Expert and Rapporteur, FP7 Photonics hearings and shortlisting, NoE and IP projects, November
2007
General Chair and Organizing Committee, Intl. Conference on “The Grand Challenges of
Photonics”, D-Munich, June 2007
General Chair and Program Committee, Intl. Conference on Frontiers in Electronic Imaging, D-
Munich, June 2007
Member of the board of “Stakeholders in Photonics – Photonics21”, European Technology
Platform, B-Brussels
Member of the board of Espros Photonics AG, CH-Sargans
Member of the board of the European Optical Society EOS, D-Hannover
Member of the board of Zentronica AG, CH-Luzern
Member of the Curriculum Commission “Nanomedicine”, University of Liechtenstein, FL-Triesen
Program Committee, International Workshop on Dynamic 3D Imaging, D-Heidelberg, September
2007
R. P. Stanley Session Chair: SPIE Photonics West Jan 2007
M. Wiki CEO, Dynetix AG
Prizes and Awards
March 2007 – First prize of the Swiss Technology Award 2007 for the “CSEM Smallest Format Factory”
September 2007 – Award Nominee for CTI Medtech Award 2007, “The LEDDT - Platform (Laser Easy Drug Delivery Technology),
a novel injection-free method for intraepidermal delivery of large molecular weight drugs.”
October 2007 – “Dupont Prix des Matériaux 2007” award for the outstanding work of Dr. Sivashankar Krishnamoorthy for work for his
thesis carried out at CSEM.
132

Headquarters
CSEM Centre Suisse d’Electronique
et de Microtechnique SA
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T +41 44 497 1411
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CSEM Alpnach
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T +41 41 672 7511
F +41 41 672 7500
CSEM Landquart
Schulstrasse 1
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T + 41 81 330 0970
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