Design and Analysis of a Novel MEMS Piezoresistive Pressure Sensor with Annular Groove Membrane and Centre Mass for Low Pressure Measurements

Abstract Purpose: Micro Electronic Mechanical System (MEMS) based pressure sensors have found their use in multiple applications lately in the field of healthcare, automotive etc. These sensors however face a trade-off between sensitivity and linearity which limits sensor performance. The proposed design aims to achieve an enhanced sensor performance by alleviating the sensitivity and linearity trade-off. Methods: Novel structures such as annular grooves and center mass have been introduced for providing better sensor performance along with membrane dimension optimization. Annular grooves generate Stress Concentrated Regions (SCRs) on membrane surface on application of external pressure which enhances sensor sensitivity while center mass provides partial stiffening of the membrane and hence reduces non-linearity. Results : The proposed sensor achieves a low non-linearity error of 0.15% FSS with a well-balanced sensitivity of 28.0 mV/V/psi. Conclusion : The proposed novel sensor structure achieves a relatively better performance in comparison to conventional membrane variants. With a high sensitivity and appreciable linearity, the novel structure proves to be ideal for low pressure measurements in the range (0-5)KPa.