柔性MEMS流速传感器的测控电路设计与实验

Design and Experiment of Measurement and Control Circuits for Flexible MEMS Flow Sensor

针对MEMS流速传感器量程小及无法应用于曲面的不足,设计制造了一种柔性MEMS流速传感器,其结构主要包含加热电阻和3对测温热电阻,同时结合热损失和热温差工作原理来实现宽量程的流速测量。设计了带温度补偿的双惠斯登电桥测控电路,利用STM32微处理器ADC模块对多路流速测量结果进行采样。测试实验实现了0～32 m/s的输入风速测量,其中在1 m/s以下的低风速段内传感器具有100 m V/(m·s^(-1))的较高灵敏度,在风速(1～7 m/s)和(7～32 m/s)下的灵敏度分别为83.1 m V/(m·s^(-1))和28.3 m V/(m·s^(-1))。该柔性MEMS流速传感器可贴于曲面应用,测量范围大、精度高。

In view of problems of the existing MEMS flow sensors has small measuring range and not being applied to the curved surface,a type of flexible MEMS flow sensor,which mainly includes heating resistor and three pairs of temperature-measuring resistor,was designed and fabricated,and wide measuring range of flow rate can be achieved by the combination of working principles of anemometer and calorimetric flowmeter.The measuring circuits of constant temperature difference based on double Wheatstone bridges were designed,and ADC module of STM32 microprocessor chip was applied to sample output signals of multichannel flow rate measurements.The test results show that the flow sensor could measure the input wind speed in the range of 0 to 32 m/s,and the sensor has a high sensitivity at low wind speed under 1m/s is about 100 mV/(m·s-1),and the sensitivities at high wind speeds of(1~7 m/s)and(7~32 m/s)were 83.1 mV/(m·s-1)and 28.3 mV/(m·s-1)respectively.This proposed flexible MEMS flow sensor can be applied to the curved surface with wide measurement range and high precision.