一种MEMS扭摆式强磁场测量传感器

摘要

提出了一种扭摆式结构的MEMS电容式强磁场传感器,采用洛伦兹力驱动,通过测量硅板扭摆导致的电容变化来检测外部磁场强度,测量磁场的量程设计在0.2 T~2 T之间.首先介绍了传感器的工作原理,然后对其进行仿真,分析其物理特性,建立了模型并且求解出各阶模态下的振动形式,得到传感器主振模态频率为28.26 kHz.并模拟了受力过程中的形变量.最后介绍了其制造工艺流程,验证了传感器加工的可行性.%A novel MEMS magnetic field sensor based on a torsional pendulum structure is presented.The amplitude of the vibration,which is proportional to the magnetic field,is detected by sensing capacitors.The measuring range of the sensor is designed to vary from 0.2 T to 2 T.The excitation of the resonator is achieved by the Lorentz force generated by a sinusoidal current flowing through a metal coil,which is deposited on the surface of the structure.The resonance frequencies and modes of the resonators are simulated by the general purpose finite element program,with the frequency of the first mode being 28.26 kHz.Furthermore,the manufacture process of the sensor is proposed to illustrate the feasibility of the device.