Sensitivity enhancement and temperature compatibility of graphene piezoresistive MEMS pressure sensor

Abstract

MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Due to recent growth in smart microsystem technology for automation systems, demand has grown substantially for sensors. High sensitivity, flexibility, miniaturization and bulk production are some of the key factors of a pressure sensor in achieving new heights in the MEMS market. In this paper, Graphene piezo resistive material has been analysed for pressure sensing elements and compared with Polysilicon in terms of sensitivity and sensor performance degradation at different temperature. MEMS pressure sensors using Polysilicon and Graphene piezo resistive materials were simulated on silicon (100) substrate by COMSOL Multiphysics 5.3a version. The simulation result shows that at room temperature polysilicon pressure sensor performs well with pressure sensitivity of 3.81 mV/psi as well as it is found that graphene pressure sensor also shows better results at room temperature showing a pressure sensitivity of 3.98 mV/psi. As on frequently increasing the temperature it is noticed that polysilicon pressure sensitivity degrades with a factor of 0.64 mV/psi. However, graphene pressure sensor shows very less variation in sensitivity at higher temperature. Although it shows a small increment of 0.02 mV/psi in the pressure sensitivity. This analysis opens the path to utilise the graphene pressure sensor at high temperature.