A comparative study on piezoelectric and piezoresistive pressure sensor using COMSOL simulation

Abstract

For system stability monitoring, pressure is one of the major and easy quantity to be measured among the many other physical quantities. A pressure sensor produces a signal as a function of the pressure imposed. These sensors became a vital part of our everyday life from devices we use at home to industrial equipment. In this paper, simulation, and comparative study of piezoresistive and piezoelectric pressure sensor is presented. All the simulations where made using COMSOL Multiphysics software of 5.5 version. Using this software, 3D models of sensors are simulated with different materials. From this simulation results, best materials for piezoelectric and piezoresistive pressure sensor are selected. This work follows the simulation, and analysis of a piezoresistive pressure sensor, done using four different sets of piezoresistive materials. Both p-type and n-type single crystalline silicon and polycrystalline silicon materials are used for the piezoresistive pressure sensor simulation. Pressure vs. displacement graphs of four set of piezoresistive materials are plotted. Displacement which is obtained in micrometer range increases with different input load from 100 KPa to 500 KPa. A piezoceramic tube, example for piezoelectric pressure sensor simulation also carried out using different piezoelectric materials like PZT 5A, PZT 5H, PVDF, BaTiO3, Lithium Tantalate, Cadmium Sulfide, Lithium Niobate, Aluminum Nitride and Barium Sodium Niobate. The modelling and simulation of Piezoceramic tube- Piezoelectric pressure sensor is done by giving different input pressure values. During the simulation of direct piezoelectric effect, voltage generation is obtained according to the input pressure. Output voltages of different piezoelectric materials are taken by giving different boundary load from 0.1 MPa to 1 MPa. Indirect piezoelectric effect simulation is also done, where piezoelectric materials become strained when the electric field is applied and this strain is directly proportional to the electric field. A Displacement table of indirect piezoelectric effect is measured by giving constant input pressure of 0.1 MPa. Here, analyses are done in MPa range of input pressures, obtained voltage in V and displacement in micrometers. Pressure vs. Voltage values for direct piezoelectric effect is plotted Efficiency and resolution of piezoresistive and piezoelectric pressure sensors are found out.