Issue 10 Volume 41 May 16, 2003

20030033836 Florida Univ., Gainesville, FL
Ultrasensitive Biosensors for Molecular Recognition and Manipulation
Tan, Weihong; Feb 2003; 8 pp.; In English
Contract(s)/Grant(s): N00014-98-1-0621
Report No.(s): AD-A410625; No Copyright; Avail: CASI; A02, Hardcopy
Our objective is to develop novel biomolecule recognition mechanisms and ultrasensitive biosensors for direct, real-time
biochemical imaging and sensing. These biosensors will provide a novel tool which permits major advances in the
investigation and control of fundamental molecular and cellular physiological processes. There are three aspects of our
approach: 1. Using nanotechnology and existing sensing mechanisms for nanometer level biosensor development; 2. Using
molecular beacon DNA molecules for development of new biomolecule recognition mechanisms; 3. Using single molecule
microscopy techniques for molecular interaction studies. Over the three years of this grant, we have published 20 papers and
filed two patents (one granted and one pending). The grant also has helped us to train six graduate students, three postdoctoral
researchers, five undergraduate students. Among all the students, there are two African American graduate students, one
Hispanic graduate student and three minority undergraduate students. The grant has also enabled us to build a world class
research laboratory in the area of biomolecular interaction and recognition studies.
DTIC
Bioinstrumentation; Detection; Chemical Properties; Molecules
20030033843 Lawrence Livermore National Lab., Livermore, CA
Polarized Light Propagation in Biologic Tissue and Tissue Phantoms
Sankaran, V.; Walsh, J. T.; Maitland, D. J.; Dec. 10, 1999; 16 pp.; In English
Report No.(s): DE2002-791683; No Copyright; Avail: Department of Energy Information Bridge
Imaging through biologic tissue relies on the discrimination of weakly scattered from multiply scattered photons. The
degree of polarization can be used as the discrimination criterion by which to reject multiply scattered photons. Polarized light
propagation through biologic tissue is typically studied using tissue phantoms consisting of dilute aqueous suspensions of
microspheres. We show that, although such phantoms are designed to match the macroscopic scattering properties of tissue,
they do not accurately represent biologic tissue for polarization-sensitive studies. In common tissue phantoms, such as dilute
Intralipid and dilute 1-microm-diameter polystyrene microsphere suspensions, we find that linearly polarized light is
depolarized more quickly than circularly polarized light. In dense tissue, however, where scatterers are often located in close
proximity to one another, circularly polarized light is depolarized similar to or more quickly than linearly polarized light. We
also demonstrate that polarized light propagates differently in dilute versus densely packed microsphere suspensions, which
may account for the differences seen between polarized light propagation in common dilute tissue phantoms versus dense
biologic tissue.
NTIS
Medical Electronics; Imaging Techniques; Polarized Light
20030033862 NASA Goddard Space Flight Center, Greenbelt, MD, USA
Design and Fabrication of Two-Dimensional Semiconducting Bolometer Arrays for the High Resolution Airborne
Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC-II)
Voellmer, George M.; Allen, Christine A.; Amato, Michael J.; Babu, Sachidananda R.; Bartels, Arlin E.; Benford, Dominic
J.; Derro, Rebecca J.; Dowell, C. Darren; Harper, D. Al; Jhabvala, Murzy D.; [2002]; 10 pp.; In English; SPIE Conference
on Astronomical Telescopes and Instrumentation, 22-28 Aug. 2002, Waikoloa, HI, USA; Original contains black and white
illustrations; Copyright; Avail: CASI; A02, Hardcopy
The High resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II
(SHARC II) will use almost identical versions of an ion-implanted silicon bolometer array developed at the National
Aeronautics and Space Administration’s Goddard Space Flight Center (GSFC). The GSFC ‘Pop-up’ Detectors (PUD’s) use
a unique folding technique to enable a 12 x 32-element close-packed array of bolometers with a filling factor greater than 95
percent. A kinematic Kevlar(trademark) suspension system isolates the 200 mK bolometers from the helium bath temperature,
and GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation.
The JFET preamps operate at 120 K. Providing good thermal heat sinking for these, and keeping their conduction and radiation
from reaching the nearby bolometers, is one of the principal design challenges encountered. Another interesting challenge is
the preparation of the silicon bolometers. They are manufactured in 32-element, planar rows using Micro Electro Mechanical
Systems (MEMS) semiconductor etching techniques, and then cut and folded onto a ceramic bar. Optical alignment using
specialized jigs ensures their uniformity and correct placement. The rows are then stacked to create the 12 x 32-element array.
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