Piezoelectric Double Layer Pressure Sensors: An Analytical Study and Multiphysics Simulation

This study presents both the analytical modeling and simulation of a cantilever pressure sensor with double-layer piezoelectric materials, specifically ZnO and PVDF, which have negative and positive voltage coefficients, in order to investigate the performance of the sensor and to validate the analytical model with simulation. A detailed three-dimensional sensor model was developed in FEM, comprising gold (Au) as electrodes, silicon dioxide (SiO2) as an insulating layer, and silicon (Si) as a substrate. Simulations performed across a pressure range of 0–10 kPa revealed a linear output voltage response, and the average margin of error (MoE) between the calculated and simulated values is approximately 11.8%. The observed net potential difference exhibited a negative polarity, primarily due to the dominant effect of ZnO, which has negative piezoelectric voltage coefficients. Comparison of analytical and simulated results shows close agreement, with slope values of −1.16 mV/kPa and −1.03 mV/kPa, respectively, validating the FEM model’s accuracy. From the analytical model, it is observed that the sensitivity of the sensor varies with piezoelectric voltage coefficients, stress produced on the piezoelectric surface and the thickness of the piezoelectric material. Various simulation results show that the output voltage increases as the thickness of ZnO and PVDF decreases.