MEMS Electric Field Sensor Based on Piezoelectric Driving and Electrostatic Induction

This paper presents a novel piezoelectrically driven, charge-sensing micro electric field sensor. The sensor operates by driving a beam that causes a shielding plate to oscillate periodically under an applied driving voltage. When the sensor is placed in an external electric field, the periodic movement of the shielding electrode induces charges on the sensing electrode. These induced charges generate a measurable induced current in an external circuit, from which the magnitude of the external electric field can be deduced. Theoretical analysis combined with finite element simulation was first used to derive the theoretical output response of the sensor. The device was then fabricated using a commercial Silicon on Insulator (SOI) process. The proposed MEMS electric field sensor features a low driving voltage, effectively reducing power consumption. It also exhibits a linear output response and excellent sensitivity, greatly simplifying the sensor's signal processing circuitry and minimizing interference. These characteristics make it well-suited for industrial electric field measurement applications.