基于锆钛酸铅的低电压驱动MEMS电场传感器研究

该文提出一种基于锆钛酸铅(PZT)的低电压驱动微机电系统(MEMS)电场传感器。该传感器基于电荷感应原理，其敏感单元由固定电极和可动电极构成。固定电极与可动电极均为感应电极，同时两者又是屏蔽电极。在PZT压电材料的驱动下，可动电极产生垂直于敏感芯片基底的振动并且与固定电极形成交互屏蔽，当存在待测电场时，分别在可动电极和固定电极上产生相位差为180°的感应电流信号。该文进行了传感器的设计和有限元仿真，提出敏感微结构的加工工艺流程，突破了基于PZT压电材料的可动电极MEMS工艺兼容制备技术，完成了敏感芯片制备，对传感器进行了性能测试。该传感器具有工作电压低的突出优点。实验测试表明，在0～50 kV/m电场强度范围内，采用1 V交流驱动电压，电场传感器的灵敏度为0.292 mV/(kV/m)，线性度为2.89%。

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° 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 0～50 kV/m electric field intensity.