In situ Observation of Actual Contact Area

Abstract

The real time observation of nanoscale deformation is a significant step toward understanding the mechanisms of friction, wear and lubrication. Our experimental system of a micromachine combined with a TEM enabled us to measure the deformation, force and actual contact area of a single Ag and Fe asperity. The experimental results provided insight into one of the parameters that determines the frictional coefficient. Furthermore, we demonstrated that the energy loss associated with a separation event is correlated with the increase in total surface energy of the two surfaces formed here after the separation of the nano-contact.