Mechanics of nanoscale wrinkling of graphene on a non-developable spherical surface

TL;DR

This paper investigates the nanoscale wrinkling behavior of graphene on spherical surfaces through a combined theoretical and simulation approach, revealing the conditions for conformation versus wrinkling and providing design insights for nanodevices.

Contribution

It introduces a theoretical model predicting graphene morphology on spherical surfaces and verifies it with molecular simulations, advancing understanding of nanoscale wrinkling phenomena.

Findings

Critical cone angle for graphene conformation identified

Theoretical predictions match molecular simulation results

Guidelines for designing graphene-based nanodevices provided

Abstract

The configuration of graphene (GE) sheet conforming to the spherical surface substrate is studied through theoretical model and molecular simulations. Two basic configurations are observed: fully conformation and wrinkling. The final configuration of the adsorbed GE results from the competition between two energy terms: the adhesion energy between GE and substrate, the strain energy stored in the GE due to the deformations. Here, we derive theoretical solutions by accounting for two energy terms, and predict the final morphology of GE on the spherical surface (a special kind of nano-developable curved surface) substrate with using the phase diagram. A critical cone angle of the absorbed GE for an arbitrary spherical surface substrate is obtained. Fully conformation of GE is observed when the cone angle of absorbed GE is below the critical value, otherwise wrinkles appear. Molecular simulations are implemented to verify the theoretical model with results agree well with theoretical predictions. Results from our present work can offer a guide for designing new functional graphene electronical devices (such as nanoswithes) and fabricating high quality nanostructured coating (Fig. 13).