Structural lubricity: Role of dimension and symmetry

Department of Applied Mathematics, University of Western Ontario London, Ontario, Canada N6A 5B7

Received: 25 November 2003
Accepted: 22 January 2004

Abstract

When two chemically passivated solids are brought into contact, interfacial interactions between the solids compete with intrabulk elastic forces. The relative strength of these interactions, which are length scale dependent, will be estimated using scaling arguments. Whenever elastic interactions dominate on all length scales, solids will move as essentially rigid objects. This would imply superlow kinetic friction in UHV, provided wear was absent. The results of the scaling study depend on the symmetry of the surfaces and the dimensionalities of interface and solids. Some examples are discussed explicitly such as contacts between disordered three-dimensional solids and linear bearings realized from multiwall carbon nanotubes.