MEMS-Based Diaphragm Pressure Sensor using S-shaped Piezoresistors for Enhancing Sensitivity

Abstract

Microelectromechanical system based silicon diaphragm pressure sensor using S-shaped piezoresistors with four grooves has been proposed for pressure measurement in the range of 0 to 1.02 kg.cm-2. Four voids are located between every two grooves where the piezoresistors are placed. These piezoresistors are electrically connected with aluminium wires to form a Wheatstone bridge. By introducing grooves around the diaphragm, more stress is concentrated in the void regions, resulting in high sensitivity. In addition, improvement in the performance of the sensor has been attained by modifying its geometrical dimensions. On the basis of simulation experiments, the proposed pressure sensor has achieved a high sensitivity in the range of 45.41 mV/V/Kg.cm-2 to 48.25 mV/V/kg.cm-2 by taking different lengths of piezoresistors varying from 300 μm to 120 μm. The pressure sensor has a very low nonlinearity compared to other pressure sensors within this range. The design and simulation of the proposed piezoresistive pressure sensor is carried by using COMSOL Multiphysics 5.2a.