New Design of Mems piezoresistive pressure sensor

Document Type: Original Article

Authors

Electrical Engineering, Islamic Azad University, Ahar Branch, Ahar, Iran

Abstract

The electromechanical analysis of a piezoresistive pressure microsensor with a square-shaped diaphragm for low-pressure biomedical applications is presented. This analysis is developed through a novel model and a finite element method (FEM) model. A microsensor with a diaphragm 1000 „m length and with thickness=400 µm is studied. The electric response of this microsensor is obtained with applying voltage into senseor in p-type piezoresistors located on the diaphragm surface.
The diaphragm that is 10 „m thickexhibits a maximum deflection of 3.74 „m using the designed model, which has a relative difference of 5.14 and 0.92% with respect to the comsol model, respectively. The maximum sensitivity and normal stress calculated using the this model are 1.64 mV/V/kPa and 102.1 MPa, respectively. The results of the polynomial model agree well with the Timoshenko model and FEM model for small deflections. In addition, the designed model can be easily used to predict the deflection, normal stress, electric response and sensitivity of a piezoresistive pressure microsensor with a square-shaped diaphragm under small deflections.

Keywords