Tunable biaxial strain device for low dimensional materials

TL;DR

This paper introduces a compact, tunable biaxial strain device for two-dimensional materials, achieving high uniformity and maximum deformation comparable to larger devices, validated through modeling and Raman spectroscopy.

Contribution

A novel compact device enabling controlled, uniform biaxial strain application on 2D materials with performance comparable to larger systems.

Findings

Device achieves high uniformity and maximum strain.

Finite element analysis confirms performance.

Raman spectroscopy demonstrates effective strain application.

Abstract

Strain is attracting much interest as a mean to tune the properties of thin exfoliated two-dimensional materials and their heterostructures. Numerous devices to apply tunable uniaxial strain are proposed in the literature, but only few for biaxial strain where there is often a trade-off between maximum strain and uniformity, reversibility and device size. We present a compact device that allows the controlled application of uniform in-plane biaxial strain, with maximum deformation and uniformity comparable to those found in much larger devices. Its performance and strain uniformity over the sample area are modeled using finite element analysis and demonstrated by measuring the response of exfoliated 2H-MoS$_2$ to strain by Raman spectroscopy.