Piezoresistive Properties of Suspended Graphene Membranes under Uniaxial and Biaxial Strain in Nanoelectromechanical Pressure Sensors

TL;DR

This paper investigates the piezoresistive behavior of suspended graphene membranes under uniaxial and biaxial strains, combining experimental measurements with theoretical modeling to enhance understanding of their application in nanoelectromechanical pressure sensors.

Contribution

It provides the first comprehensive experimental and theoretical analysis of both uniaxial and biaxial piezoresistive effects in suspended graphene membranes for pressure sensing.

Findings

Gauge factor is independent of doping and orientation.

The linearized Boltzmann transport model accurately predicts charge mobility.

Piezoresistive properties are characterized under different strain conditions.

Abstract

Graphene membranes act as highly sensitive transducers in nanoelectromechanical devices due to their ultimate thinness. Previously, the piezoresistive effect has been experimentally verified in graphene using uniaxial strain in graphene. Here we report experimental and theoretical data on the uni- and biaxial piezoresistive properties of suspended graphene membranes applied to piezoresistive pressure sensors. A detailed model that utilizes a linearized Boltzman transport equation describes accurately the charge carrier density and mobility in strained graphene, and hence the gauge factor. The gauge factor is found to be practically independent of the doping concentration and crystallographic orientation of the graphene films. These investigations provide deeper insight into the piezoresistive behavior of graphene membranes.