基于MEMS技术悬臂梁式脉搏传感器制作与特性研究

Fabrication and Characteristics Research of the Cantilever Beam Pulse Sensor Based on MEMS Technology

摘要: 本文给出悬臂梁式脉搏传感器，该结构由硅悬臂梁和悬臂梁根部四个压敏电阻构成的惠斯通电桥结构组成。基于压阻效应，当悬臂梁顶端受到脉搏力F作用时，悬臂梁发生弹性形变，引起四个扩散压敏电阻阻值发生变化，桥路输出电压变化，实现对脉搏力F的测量。基于MEMS技术在<100>晶向单晶硅衬底实现传感器芯片制作和封装，当工作电压V_DD = 5.0 V时，外力F = 100 mg作用下悬臂梁输出电压为111 mV，传感器灵敏度为0.54 mV/mg，准确度为5.90% F.S.。实验结果表明，该悬臂梁结构可实现脉搏力F测量且灵敏度较高。

Abstract: This paper presents the cantilever beam pulse sensor, and the structure consists of the silicon cantilever beam and Wheatstone bridge that contains cantilever beam roots four piezoresistors. Based on the piezoresistive effect, when the cantilever top was touched by pulse force, the elastic deformation of the cantilever beam occurred, which induced the change of the piezoresistive value and the bridge output voltage, and finally the measurement of the pulse was realized. Based on the sensor chip fabrication and packaging on the <100> orientations silicon substrate, when supply voltage V_DD = 5.0 V, the cantilever beam output voltage is 111 mV under the 100 mg external force, the sensor sensitivity is 0.54 mV/mg, and the accuracy rating is 5.90% F.S. Experimental results show that the cantilever beam structure enables accomplish pulse measurement and possesses high sensitivity.