Design and optimization of a micro piezoresistive pressure sensor

This paper focuses the structural design and optimisation of the micro piezoresistive pressure sensor to enhance the sensitivity and linearity. Finite element method (FEM) is adopted to optimize the sensor parameters, such as the resistor location and number of turns. An absolutely type pressure sensor with 150kPa full scale span (FSS) is built based on the optimal design programme as well as the bulk-micromachined process. For an 1150-mu m-wide 30-mu m-thick square-shape pressure sensor, experimental results show that the sensitivity of 2.3mV/V/10kPa, linearity error of 0.57% FSS and pressure hysteresis of 0.04% FSS are achieved. The well compatibility between the results of simulation and testing certifies the validity of the optimized scheme.