Design and modelling of a micro resonant pressure sensor

Abstract

A silicon island compliant mechanism supported frequency tunable resonating beam based micro pressure sensor is proposed in this work. The sensor consists of a silicon frame with silicon islands supporting a silicon nitride resonating beam placed diagonally on the island in a square diaphragm made of silicon. The analytical model of the sensor is developed by modelling the diaphragm having islands as non uniform sections and the resonating beam under axial tensile load. The sensor is numerically modelled and its dimensions are optimized using MEMS CAD Tool COVENTORWARE. The performance of the proposed sensor is evaluated through simulation for a pressure range of 0–20 bar. The results demonstrate that the sensor is linear and its characteristics obtained from the analytical and numerical model are in close agreement. The sensitivity of the sensor is compared with the sensitivity of a sensor having islands and the resonating beam placed between two opposite sides of the diaphragm and found to have 5 % increment in sensitivity.