Atomistic Simulations of Friction at Sliding Diamond Interfaces

Abstract

Friction, or the resistance to motion of two bodies in contact, and the related phenomenon of wear are two of the more costly problems facing industry today. Despite their importance, a fundamental understanding of friction and wear, especially at the atomic scale, has remained elusive. This is rapidly changing, however, as new scientific instrumentation has been developed that allows, for the first time, the study of friction at the atomic scale. These pioneering efforts have led to the emergence of a rapidly growing field called nanotribology, the subject of this issue of the MRS Bulletin. Some of the contributing techniques include the surface force apparatus, which has been used to study the rheology of molecularly thin liquid layers, a quartz-crystal microbalance, which has been used to measure the sliding friction of molecularly thin adsorbed films, and the atomic force microscope (AFM), which has been used to measure the frictional force between a sharp tip (possibly a single asperity) and a flat surface during sliding. In addition to providing a vast amount of information related to friction on the atomic scale, these innovative experiments have provided the necessary data to test the validity of older theoretical models and have stimulated new theoretical work. For instance, atomic-scale friction has been investigated theoretically using analytic models, first principles calculations, and molecular dynamics simulations.