Frictional Dissipation and Scaling Laws at van der Waals Interface: The Key Role of Elastic Pinning of Moir\'e at Edges and Corners

TL;DR

This study uses atomistic simulations to show how elastic pinning at edges and corners influences friction at van der Waals interfaces, and how shaping and twisting sliders can control energy dissipation for large-scale superlubricity.

Contribution

It reveals the dominant role of incomplete moiré pinning at edges in friction and proposes shape and twist control as methods to achieve scalable superlubricity.

Findings

Edge pinning dominates friction at nano- to microscales.

Shaping and twisting sliders can control energy dissipation.

Controlling interfacial pinning enables large-scale superlubricity.

Abstract

Van der Waals heterogeneous interfaces are promising candidates for the scaling up of structural superlubricity to meet practical applications. Several factors, however, have been identified that may eliminate superlubricity. Elasticity is one such intrinsic factor, where shear induced lattice reconstruction leads to local interfacial pinning, even at clean pristine contacts. Here, through detailed atomistic simulations, we reveal that incomplete moir\'e tile pinning at the corners and edges of finite sliders dominates friction from the nano- to the microscales. We further demonstrate that slider shape tailoring and twisting allow to control energy dissipation and its scaling with contact size, thus opening the way to achieve large-scale superlubricity.