Colloquium on September 28, 2009

Robert W. Carpick
University of Pennsylvania

New insights into dissipative processes: Damping, adhesion, friction, and wear at the nanometer and atomic scale

Micro- and nano-scale experiments and devices, nanostructured materials, and a vast array of biological systems possess interfaces and mechanical contacts of extremely small size. Correspondingly, adhesive interactions, friction, interfacial chemistry, and wear have tremendous influence on the behavior of these systems, and surfaces and interfaces become the primary regions where energy is dissipated. The underlying physical phenomena that control these processes are yet to be well-understood or controlled. I will review specific systems and applications where these dissipative processes are critical, including nanocomposites, nanomanufacturing, micro/nano-devices, and biological systems. I will then discuss experimental methodologies for measuring and understanding nanoscale dissipation through the use of atomic force microscopy (AFM). Finally, I will highlight recent measurements that focus on atomic-scale studies of the origins of wear, and atomic-scale stick-slip dissipation in atomically-thin structures.