Noncontact Atomic Force Microscopy - Yale School of Engineering ...

P.II-18
Development of a NC – AFM for Ambient and Liquid Environments
Haider I. Rasool 1 , Shivani Sharma 1 , James K. Gimzewski 1,2,3
1 Department of Chemistry and Biochemistry, University of California – Los Angeles, USA
2 California NanoSystems Institute, 570 Westwood Plaza, Los Angeles, USA.
3 International Center for Materials Nanoarchitectonics (MANA), Tsukuba, Japan
High resolution Non – Contact Atomic Force Microscopy imaging has been
achieved by various groups in both ambient and liquid environments [1] – [3]. The recent
success of NC – AFM in these “low – Q” environments has been attributable to the
development of low noise detection schemes for measuring small amplitude deflections.
We describe current research on the development of a robust home – built scanning probe
microscope with an incorporated low noise all fiber interferometer deflection sensor for
imaging in both ambient and liquid environments. The current design of the scanning
probe microscope in its AFM configuration is depicted in Figure 1 (a).
The developing instrument has been used to image various biological species in
both ambient and liquid environments in different imaging modes. In particular, our
group has been successful in imaging isolated human saliva exosomes fixed to a mica
substrate in both air and buffer solution. Both amplitude and phase modulation imaging
have been accomplished on these samples under ambient conditions. Using constant
excitation phase modulated imaging, a simultaneous mapping of topography and energy
dissipation has been possible at a constant average tip sample force. Figure 1(b) shows a
typical image of the topography of an isolated exosome.
a) b)
Figure 1: The above images show (a) the design of the home built microscope and (b) a PM –
AFM image of a human saliva exosome.
[1] T. Fukuma, M. Kimura, K. Kobayashi, K. Matsushige, and H. Yamada. Rev. Sci. Instrum. 76, 053704
(2005).
[2] B.W. Hoogenboom, H.J. Hug, Y. Pellmont, S. Martin, P.L.T.M. Frederix, D. Fotiadis,and A. Engel.
Appl. Phys. Lett. 88, 193109 (2006).
[3] T. Fukuma, and S. Jarvis. Rev. Sci. Instrum. 77, 043701 (2006).
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