Design and Simulation of High ‘g’ and Low Cross Axis Sensitivity Single Axis Piezoresistive MEMS Accelerometer

In this work the design of a single axis micro electro mechanical system (MEMS) accelerometer based on piezoresistive sensing has been presented. The accelerometer design is based on cantilever consisting of a proof mass supported by four thin flexural beams which are fixed at the supporting frame ends along with piezoresistors employed over these fixed ends of the flexures for maximum sensitivity. The sensor has been designed for optimum performance and characterized using finite element method (FEM) CAD tools achieving low cross axis sensitivity, acceleration range of 500g and showing linear performance. Its sensitivity was observed to be 0.225mV/g along the sensing axis (z axis) and the cross axis sensitivities along x and y axes were found to be as low as 0.525 ?V/g and 0.546 ?V/g respectively that are merely 0.234 % and 0.243 % of the z axis sensitivity. Also, the bandwidth of the sensor was found to be 5.868 kHz giving high figure of merit of 61171.96 m-1. The proposed sensor structure is of compact size and is observed to be of superior performance in comparison to the reported sensors. Hence the present design can possibly be used for high acceleration measurements with low cross axis sensitivity and higher bandwidth.