Tearing of Free-Standing Graphene

TL;DR

This study investigates the fracture mechanics of free-standing graphene under out-of-plane forces using molecular dynamics simulations, providing insights into crack propagation, failure energetics, and methods to measure toughness.

Contribution

It introduces a simulation-based analysis of crack propagation in graphene under out-of-plane forces and proposes a new method to determine graphene's toughness.

Findings

Crack path depends on initial crack length.

Derived analytical expressions for critical crack lengths and forces.

Proposed a method to measure graphene's toughness.

Abstract

We examine the fracture mechanics of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free-standing graphene as a function of the out-of-plane force. The geometry is motivated by experimental configurations that expose graphene sheets to out-of-plane forces, such as back-gate voltage. We establish the geometry and basic energetics of failure, and obtain approximate analytical expressions for critical crack lengths and forces. We also propose a method to obtain graphene's toughness. We observe that the cracks' path and the edge structure produced are dependent on the initial crack length. This work may help avoid the tearing of graphene sheets and aid the production of samples with specific edge structures.