Multiphysics simulation of piezoresistive pressure microsensor using finite element method

Abstract

In this study, the electro-mechanical behavior of a specially designed highsensitive piezoresistor pressure microsensor was simulated using finite element method, through COMSOL multiphysics software. The mechanical deformation of the diaphragm and the distribution of electrical potential in the piezoresistive were evaluated for various pressure values. In order to determine the influence of the temperature sensitivity parameter, different temperature conditions were investigated. According to the obtained results, by increase of the applied pressure, the resistance of the piezoresistor decreased, while, the sensitivity increased. Also, it was observed that at constant pressure, as the temperature increases, the stress on the diaphragm surface decreases, indicating high stress distribution at the sides and the middle of the diaphragm at low temperatures such as -50 °C. Furthermore, the obtained results demonstrated that temperature variations were not very effective on the potential distribution in the piezoresistor. However, the temperature coefficient of sensitivity demonstrated an increasing tendency with increase of the temperature from -50 °C to 50 °C.