Observation of a Snap-Through Instability in Graphene

TL;DR

This study investigates the snap-through transition in graphene on corrugated substrates, revealing a critical thickness where graphene switches from conforming to flat, and estimates a higher-than-expected adhesion energy.

Contribution

The paper demonstrates a sharp snap-through instability in graphene and provides a novel method to measure adhesion energy using this transition.

Findings

Identified a critical thickness for snap-through transition.

Measured graphene-surface adhesion energy exceeding van der Waals expectations.

Validated the elasticity model for graphene bending on substrates.

Abstract

We examine the competition between adhesive and bending energies for few-layered graphene samples placed on rigid, microscale-corrugated substrates. Using atomic force microscopy, we show that the graphene undergoes a sharp "snap-through" transition as a function of layer thickness, where the material transitions between conforming to the substrate and lying flat on top of the substrate. By utilizing the critical snap-through thickness in an elasticity model for the FLG's bending, we extract a value for graphene-surface adhesion energy that is larger than expected for van der Waals forces.