Research on MEMS Electric Field Sensor with Low Driving Voltage Based on Lead Zirconate Titanate

A Micro-Electro-Mechanical System (MEMS) electric field sensor with low driving voltage based on Lead Zirconate Titanate (PZT) is proposed. Based on the charge-induction principle, the sensitive units are composed of fixed electrodes and movable electrodes. All the fixed and movable electrodes work as sensing electrodes, in the meantime, they are also mutually shielding electrodes. Driven by the piezoelectric material PZT, the movable electrodes vibrate perpendicularly to the substrate of the sensitive chip, and they are mutually shielded with the fixed electrodes. When there is an electric field to be measured, induced current signals with a phase difference of 180 degrees are generated respectively on the movable electrodes and the fixed electrodes. The design and finite element simulation of the sensor are carried out, the fabrication process of the sensitive microstructure is proposed, the MEMS process compatible preparation technology of movable electrode based on PZT piezoelectric material is broken through, the microsensor chip is successfully produced, and the performance of the sensor is tested. The sensor has the advantage of low working voltage. Experimental results show that, with 1 V AC driving voltage, the sensitivity of the electric field sensor system is 0.292 mV/(kV/m) and the linearity is 2.89% in the range of 0 similar to 50 kV/m electric field intensity.