Mechanical Control of Graphene on Engineered Pyramidal Strain Arrays

TL;DR

This study demonstrates how mesoscale pyramidal arrays can mechanically control strain in graphene, enabling tunable electronic properties through morphology manipulation and strain engineering.

Contribution

It introduces a novel method of controlling graphene strain using patterned pyramidal substrates, combining experimental and modeling approaches.

Findings

Graphene morphology can be tuned from conformal to suspended.

Non-uniform strains induce strong pseudomagnetic fields.

Pyramidal arrays enable strain-engineering in graphene devices.

Abstract

Strain can tune desirable electronic behavior in graphene, but there has been limited progress in controlling strain in graphene devices. In this paper, we study the mechanical response of graphene on substrates patterned with arrays of mesoscale pyramids. Using atomic force microscopy, we demonstrate that the morphology of graphene can be controlled from conformal to suspended depending on the arrangement of pyramids and the aspect ratio of the array. Non-uniform strains in graphene suspended across pyramids are revealed by Raman spectroscopy and supported by atomistic modeling, which also indicates strong pseudomagnetic fields in the graphene. Our results suggest that incorporating mesoscale pyramids in graphene devices is a viable route to achieving strain-engineering of graphene.