Search this Site

Print this page
RSS

April 29, 2004

Professor Arvind Raman
Mechanical Engineering
Purdue University

Title: Nonlinear physics of oscillating atomic force probes interacting with nanostructures

The oscillations of scanning probe microcantilevers are strongly influenced by the highly nonlinear interaction forces between a few atoms on the microcantilever tip and the scanned nanostructure. These tip-sample interaction forces include the van der Waals, electrostatic, surface tension, sample elasticity and Pauli repulsion forces and render highly nonlinear the dynamics of such microcantilevers.

On one hand the nonlinear dynamics of scanning probe microcantilevers can affect adversely their stability in nanoscale imaging, and probe based nanolithography applications. On the other hand, when used as sensors, their inherently nonlinear dynamics can be exploited to identify nanoscale elasticity, adhesion, and other surface forces in biological and nanotribological applications. I will discuss these issues through our recent theoretical and experimental results on (a) conventional tip tapping mode dynamics, (b) carbon nanotube (CNT) tipped tapping mode dynamics, and (c) friction force microscopy.

Brief bio:
Arvind Raman is an Assistant Professor of Mechanical Engineering at Purdue University since 2000. He received his Ph. D. Degree in Mechanical Engineering in 1999 from the University of California, Berkeley, with specializations in dynamics, continuum mechanics, and applied mathematics. Earlier he received his M.S.M.E degree in 1993 from Purdue University. As a post-doctoral researcher in 1999, at the Institute of Mechanics, Technical University-Darmstadt, Germany, he was recipient of the DAAD Scholarship for visiting scientists. He is recipient of the NSF CAREER award (2002) for his research on the nonlinear mechanics and aeroelasticity of gyroscopic systems. He is also the recipient of the Purdue Teaching for Tomorrow Award (2002) for excellence in teaching, and of the Discovery Award (2003) for singular achievement or discovery in Mechanical Engineering for his work on scanning probe microscopy. His research interests span theoretical and experimental nonlinear dynamics with applications to micro and nanoscale device dynamics, and on flow-structure interactions with applications to the vibrations of data storage and manufacturing systems. He serves on the ASME Technical Committee on Sound and Vibration, the ASME Design Engineering's sub-committee on micro- and nanosystems, and on the Advisory Committee of the Purdue Birck Nanotechnology Center.