Micro pressure sensor with three degrees of freedom resonator

In this paper a micro pressure sensor having three degrees of freedom (DOF) resonating beam is proposed. The sensor comprises of a silicon square diaphragm, silicon frame with islands supporting a 3 DOF resonating beam made of silicon nitride. The analytical model of the non uniform diaphragm with islands as non uniform segment is designed and developed. The dimensions of the diaphragm and islands are optimized for linearity, high sensitivity and high stress distribution at free edges of the island for the applied input pressure range of 0–20 bar. The 3 DOF resonator and the resonator integrated with diaphragm are modelled numerically in COMSOL and CoventorWare respectively. Sensitivity analysis is carried out using analytical and numerical model and the proposed pressure sensor with 3 DOF resonator is found to have 5 % higher sensitivity as compared to the pressure sensor designed with single DOF resonating beam.