Design and Simulation of a MEMS Piezoresistive Floating Element Shear Stress Sensor

The paper presents the modelling , simulation and comparison of a MEMS piezoresistive (PZR) floating element shear stress sensor with various dimensions which has potential applications in underwater measurements. The floating element design utilizes a plate element of small mass suspended by four tethers. PZR patches are implanted at the root of the tethers. Shear stress is inferred by the deflection in the tethers and the corresponding change in the resistance of the PZR patches. The two side wall implanted piezoresistors measure lateral force and infer the shear stress, and top-implanted piezoresistors senses the normal forces and pressure transients. Sensors with varying dimension of tether, plate geometry and gap sizes are simulated in Coventor-ware to evaluate the effects at the micro scale. The modes of vibration of the structure and resonant frequencies are obtained by modal analysis. The Mises-stress values with varying displacements of the floating element structure are obtained from Mem-mech analysis. The PZR analysis results shows that the change in the current through the PZR patches attributes to the stress developed in the tethers and can be calibrated for shear stress on the plate element. Keywords: shear stress sensor, piezoresistive, MEMS Cite this Article Augustine N, Uma G, Umpathy M. Design and Simulation of a MEMS Piezoresistive Floating Element Shear Stress Sensor. Recent Trends in Sensor Research and Technology . 2015; 2(1): 11–16p.