基于三层悬臂梁结构的电容式风速传感器设计

为解决传统电容式测风传感器的输出非线性,设计了一种基于MEMS微机械加工技术的电容式风速传感器.传感器的敏感结构创新性地采用了一个三层结构的悬臂梁,这种三层结构的悬臂梁构成了一个平行板电容器.风力作用于传感器敏感结构引起电容器的极板面积、极板间距以及绝缘层介电常数的变化,从而引起电容器输出电容的变化,通过测量传感器输出电容的变化值可以实现风速的测量.基于流体力学原理和多层悬臂梁理论对传感器进行了理论分析,并为传感器设计了制作工艺流程.

Novel Capacitive Wind Speed Sensor Based on Triple-layered Cantilever Structure

In order to ameliorate the nonlinearity of traditional capacitive wind speed sensor,a novel capacitive wind speed sensor based on bulk micromachining technology was designed, whose sensitive structure was a solid state capacitor consisting of a triple-layered cantilever. Due to wind flow applying on sensitive structure,the relative capacitor area,displacement between capacitor electrodes and permittivity of dielectric material will change. The information of wind speed can be obtained by detecting output capacitance of the sensor. The designed sensor was theoretically analyzed based on fluid mechanics principle and multilayer cantilever theory. The fabrication process was designed for the proposed sensor.