Dry Friction due to Adsorbed Molecules

TL;DR

This paper presents a theoretical model explaining the universal occurrence of dry friction through the role of mobile molecules at the interface of two crystalline surfaces, predicting how friction depends on molecular interactions.

Contribution

It introduces a realistic adiabatic approximation model that accounts for dry friction caused by adsorbed molecules, extending the Tomlinson model to this context.

Findings

Friction depends on the interaction strength between surfaces and mobile molecules.

The model predicts conditions for instabilities leading to dry friction.

Results align with the widespread observation of dry friction in various systems.

Abstract

Using an adiabatic approximation method, which searches for Tomlinson model-like instabilities for a simple but still realistic model for two crystalline surfaces in the extremely light contact limit, with mobile molecules present at the interface, sliding relative to each other, we are able to account for the virtually universal occurrence of "dry friction." The model makes important predictions for the dependence of friction on the strength of the interaction of each surface with the mobile molecules.