Atomic-scale friction: thermal effects and capillary condensation

Abstract

This work entitled as "Atomic-scale friction: thermal effects and capillary condensation" is a study on the fundamental aspects of the origin of friction from the atomic-scale. We study two realistic aspects of atomic-scale friction, namely the effect of temperature and the effect of relative humidity of the environment. To study this, we used a home-built friction force microscope (FFM) where a sharp tungsten tip was scanning over a graphite surface. We find that thermal activation of the tip reduces friction significantly, whereas the water condensing between the tip and the surface as a result of capillary condensation increases atomic-scale friction. Water condensing between the tip and the surface forms ice at room temperature and the tip writes a line of ice on the surface. Therefore, we find that water acts like a glue rater than a lubricant in atomic-scale friction.