Piezoelectric PZT Film-Driven Resonant Torsional MEMS Electric Field Sensor

Electric field measurements are crucial to monitor the electromagnetic environment in substations, measuring voltage on transmission lines, and assessing the condition of electrical equipment. This study fabricated a resonant torsional micro-electromechanical systems (MEMS) electric field sensor based on flexible piezoelectric lead zirconate titanate (PZT) thin-film actuation, aimed at addressing limitations observed in the existing and developing electric field sensor devices. The novel sensor topology was designed on the principle of charge induction, featuring a piezoelectric drive structure comprising four symmetrically distributed L-shaped cantilever beams and two pairs of staggered-coupled comb-tooth electrodes. The working principle and sensitivity of the sensor were analyzed. Using finite element software, an integrated simulation model of the structure was established for detailed modal analysis. The key structural parameters were optimized through parameter scanning, yielding an optimal design scheme. Subsequently, the fabrication process of the sensitive device was outlined, culminating in the successful preparation of the MEMS electric field sensor. Experimental validation on a dedicated platform demonstrated that the sensor exhibited robust tracking and response capabilities across high- and low-frequency sinusoidal electric fields ranging from 5 Hz to 10 kHz, without notable distortion or delay. Furthermore, the sensor achieved dc field measurement by modulating dc into ac, exhibiting good linearity in industrial frequency ac fields from 0 to 100 kV/m with a sensitivity of up to 5.64 mV/(kV/m). The results of this study offer foundational support for deploying the sensor in diverse applications within power systems, highlighting its potential for enhancing electromagnetic sensing technologies in practical settings.