Friction at the atomic scale

Abstract

The progress in nanotribology demonstrates that the laws of macroscopic friction are inapplicable at the atomic scale. The laws of friction can now generalized: first, the friction force is proportional to the degree of irreversibility of the force that squeezes the two surfaces together, rather than the outright strength of the force; second, the friction force is proportional to the actual, rather than apparent, area of contact. and lastly, the friction force is directly proportional to the sliding speed of the interface at the true contact points. The discrepancy between microscopic and macroscopic frictional phenomena lessens by noting that the true contact between macroscopic objects is likely to be proportional to the squeezing force.