Structural lubricity: Role of dimension and symmetry

TL;DR

This paper investigates how the interplay of interfacial and elastic forces, influenced by surface symmetry and dimensionality, affects frictional properties of passivated solids, with implications for superlubricity.

Contribution

It introduces a scaling framework to analyze the impact of dimension and symmetry on interfacial interactions and friction in passivated solids.

Findings

Elastic interactions dominate on all scales lead to rigid motion and superlow friction.

Surface symmetry and dimensionality critically influence interfacial behavior.

Examples include disordered 3D solids and carbon nanotube bearings.

Abstract

When two chemically passivated solids are brought into contact, interfacial interactions between the solids compete with intrabulk elastic forces. The relative importance of these interactions, which are length-scale dependent, will be estimated using scaling arguments. If 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.