Comparative Analysis of Rectangular and Circular Piezoelectric Sensor for Pressure-Based Energy Generation

Piezoelectric sensors are widely used due to their high sensitivity, fast response, and ability to convert mechanical energy to electrical signals for diverse applications in pressure sensing, wearable devices, and energy harvesting. This study investigates the design and performance analysis of two piezoelectric pressure sensors with rectangular and circular patches using COMSOL Multiphysics. Each sensor consists of a Polydimethylsiloxane (PDMS) substrate, a Polyvinylidene Fluoride (PVDF) piezoelectric layer, and aluminium electrodes on the top and bottom. Fixed boundary conditions are applied to secure the sensor's four edges, while a pressure range of 0–60 kPa is applied to its top surface using the boundary load feature in the solid mechanic interface. The electric potential interface within the electrostatic interface connects the sensor patches in series, grounding one patch's bottom electrode while terminating the other to the electric circuit interface to measure the output voltage across a 1 kΩ load. The rectangular patch sensor yields a maximum output voltage of 26 mV, while the circular patch sensor produces a higher output of 30 mV. Additionally, to enhance sensor output, the piezoelectric element is replaced with Zinc Oxide (ZnO). The sensor employing ZnO material generates a higher output voltage of 40 mV and 47 mV for the rectangular and circular patches, respectively, compared to the PVDF material. A comparative study reveals that the circular patch sensor outperforms the conventional rectangular one, offering enhanced output voltage and optimized geometry for superior performance, which makes it a better choice for pressure sensing applications.