Study Of Micro-mass Sensors

Micro-mass sensor is a new class of mass-frequency sensor being made of crystalpiezoelectric effect, which has advantages of simple structure, high sensitivity, good reliability,small size, fast response, low cost and easy integration.At present, there are three types of Quartz Crystal Microbalance, Surface Acoustic Waveand Piezoelectric Cantilever Sensors.First, in this thesis, these three types of mass sensors’ working principle in gas and liquidenvironment were analyzed and compared, the bandwidth of the oscillation circuit of theQCM sensor in the gas working environment has been focused on researching and exploring,the parameters (dielectric constants, elastic constants and piezoelectric constants)of AT-cutquartz crystal were analyzed and calculated, in theory.And then, on the experiment, the implementation and experimental study of designedLiCl–QCM humidity sensor were carried out, combined with theoretical research results andthe existing achievements of traditional LiCl humidity sensor. The experimental results showthat this type of humidity sensor inherited the dual advantages of LiCl and QCM, brokethrough the narrow range problem of traditional LiCl humidity sensor, with high sensitivity,fast response, low cost, small hysteresis, wide range, good interchangeability and excellentlinearity and good benefits.In addition, in order to enhance the anti-pollution ability of LiCl humidity sensor,improve hygroscopic deliquescence drawbacks of inorganic salt, this work further exploredthe humidity sensitive characteristics of polymer humidity sensor material based on LiCl–QCM humidity sensor, to seek a more ideal humidity sensing materials, to create a morefavorable performance of the humidity sensor.This paper from the structure of the QCM humidity sensing system, material selection,preparation of the humidity sensor to the final data extraction and analysis, experimentalresults are consistent with the theoretical prediction, achieving the desired design goals.