Experimental and Theoretical Study of the New Image Force Microscopy Principle (Invited Paper)
- PDF / 842,676 Bytes
- 13 Pages / 432 x 648 pts Page_size
- 61 Downloads / 182 Views
Theoretical Study of the New Image Force Microscopy Principle (Invited Paper) H. Kumar Wickramasinghe and Indrajith Rajapaksa MRS Proceedings / Volume 1318 / 2011 DOI: 10.1557/opl.2011.283
Link to this article: http://journals.cambridge.org/abstract_S1946427411002831 How to cite this article: H. Kumar Wickramasinghe and Indrajith Rajapaksa (2011). Experimental and Theoretical Study of the New Image Force Microscopy Principle (Invited Paper). MRS Proceedings,1318, mrsf101318vv0906 doi:10.1557/opl.2011.283 Request Permissions : Click here
Downloaded from http://journals.cambridge.org/OPL, IP address: 128.118.88.243 on 10 Aug 2012
Mater. Res. Soc. Symp. Proc. Vol. 1318 © 2011 Materials Research Society DOI: 10.1557/opl.2011.283
Experimental and Theoretical Study of the New Image Force Microscopy Principle (Invited Paper)
H. Kumar Wickramasinghe and Indrajith Rajapaksa Department of Electrical Engineering and Computer Science University of California, Irvine, CA, 92697 ABSTRACT A new technique in microscopy is demonstrated in which the domain of Atomic Force Microscopy (AFM) is extended to optical spectroscopy at the nanometer scale. Molecular resonance of feature sizes down to the single molecular level were detected and imaged purely by mechanical detection of the force gradient between the interaction of the optically driven object molecular dipole and its mirror image in a Platinum coated scanning probe tip. We provide full experimental details including a basic theory for this new technique. The microscopy and spectroscopy technique is extendable to frequencies ranging from radio to infrared and the ultra violet. INTRODUCTION AFM’s have been successfully applied to nanometer scale imaging of chemical1 magnetic2,3 and electrostatic4,5 properties of surfaces. These microscopes rely on probe tips (typically silicon) suitably modified to detect the specific property of interest and to translate it into a detectable force. AFM’s have been highly successful for mapping surface topography – reaching atomic resolution. Several approaches have also been proposed for using AFM’s to perform local optical spectroscopy of a surface. These include detecting light induced changes in contact potential difference6 and detecting the photo thermal displacement due to absorption7,8. However these techniques have a major drawback in that they are all limited in resolution by the thermal diffusion length in the sample to around 0.25 micron. Recently, we introduced a new technique – Image Force Microscopy - where an AFM is modified to perform molecular scale spectroscopy and microscopy9. In this paper, we provide a complete description of the new microscopy principle. The ability to apply AFM’s for nanometer scale spectroscopic analysis will open new opportunities in materials science and biology. In biology it could be used to study molecular cell surface interactions or for next generation DNA sequencing technologies for single base identification. EXPERIMENT Our microscope is built around an attractive tapping mode AFM10 w
Data Loading...
