Nanotribology

Abstract

Nanotribology is a study on friction phenomena occurring at nanometer scale. The distinction between nanotribology and conventional tribology is primarily due to the effect of surface forces in the determination of the adhesion and friction behavior of the system. Commercial bearings and lubricating oils reduce friction in the macroscopic machines; however, the tribological issues on small devices such as microelectromechanical systems and nanoelectromechanical systems require other solutions. Their high surface-to-volume ratio leads to severe adhesion and friction issues, which dramatically reduce their reliability and lifetime. This chapter reviews the basic concepts for handling the adhesion and friction issues at nanoscale. A brief summary on analytical models of single-asperity contact as well as the basic concepts on the surface forces occurring at nanometer gap are discussed in the first two sections, followed by three case studies: (1) experimental measurements on adhesion and friction at single-asperity contact, (2) experimental measurements on adhesion at multi-asperity contact, and (3) biomimetics: controlling nano-adhesion and nano-friction.