MEMS磁场传感器的设计及测试  

Design and experiment of MEMS magnetic sensor

作　　者：陈洁[1] 秦明[1] 黄庆安[1] 

机构地区：[1]东南大学MEMS教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2011年第5期929-933,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(61076071)

摘　　要：以U型梁为主要结构设计了一种新型的洛伦兹力驱动的磁场传感器,检测在磁场中作切割磁力线运动的金属线上的感生电压,实现磁场测量.首先介绍了传感器的工作原理,并用振动理论对传感器的受力及响应进行了分析,接着用有限元软件建立结构模型并对其振动模态和频率进行了仿真.该MEMS磁场传感器采用标准的CMOS工艺加上后处理来实现.最后用多普勒仪对传感器的频率和振动幅度进行测试,并对传感器的感生电动势与磁场、电流的关系进行了测试.实验结果与理论分析一致,该传感器的灵敏度为14 mV/mT.该传感器结构简单,测试方便,可用于对mT级的磁场进行测试.A new sensor of measuring magnetic field using a U-shaped beam driven by Lorentz force is presented.The magnetic field is obtained by measuring the induced electromotive voltage of the coil of the mechanical structure.The theoretical model and the response of the sensor are analyzed using the vibration theory.The resonance frequencies and modes of the resonators are simulated by the general purpose finite element program ANSYS.These micro-electro-mechanical systems（MEMS） devices are realized through a standard CMOS process coupled with a post-processing phase.A laser Doppler vibrometer system is implemented to measure the vibration amplitudes and the frequency of the fabricated structure.The relationship between the induced voltages of the sensor and the external magnetic field and the current is tested.And the sensor exhibits a resolution of 14mV/mT.A good agreement is observed between the predicted and observed behavior of the magnetic field sensor.The sensor is of simple structure and easy fabrication.It can be used for magnetic field of mT level.

关 键 词：磁场传感器 MEMS 洛仑兹力 谐振 

分 类 号：TP212.13[自动化与计算机技术—检测技术与自动化装置]