Stretching graphene using polymeric micro-muscles

TL;DR

This paper introduces a novel method to induce controllable, reversible strain in graphene using polymeric micro-muscles that respond to electron-beam irradiation, enabling advanced strain engineering in 2D materials.

Contribution

The study presents a new approach employing polymeric micro-muscles made of PMMA to control strain in graphene via electron-beam irradiation, offering greater flexibility for strain manipulation.

Findings

Demonstrated inhomogeneous anisotropic strain in graphene

Observed out-of-plane deformation using microscopy techniques

Showed reversible control of strain with electron-beam stimulus

Abstract

The control of strain in two-dimensional materials opens exciting perspectives for the engineering of their electronic properties. While this expectation has been validated by artificial-lattice studies, it remains elusive in the case of atomic lattices. Remarkable results were obtained on nanobubbles and nano-wrinkles, or using scanning probes; microscale strain devices were implemented exploiting deformable substrates or external loads. These devices lack, however, the flexibility required to fully control and investigate arbitrary strain profiles. Here, we demonstrate a novel approach making it possible to induce strain in graphene using polymeric micrometric artificial muscles (MAMs) that contract in a controllable and reversible way under an electronic stimulus. Our method exploits the mechanical response of poly-methyl-methacrylate (PMMA) to electron-beam irradiation. Inhomogeneous anisotropic strain and out-of-plane deformation are demonstrated and studied by Raman, scanning-electron and atomic-force microscopy. These can all be easily combined with the present device architecture. The flexibility of the present method opens new opportunities for the investigation of strain and nanomechanics in two-dimensional materials.