MEMS光纤法珀压力传感器的设计及解调方法实现

摘要

基于外界压力引起敏感膜片形变导致腔长变化来实现压力信号传感的原理，提出了一种MEMS光纤法珀压力传感器的设计，建立了传感器敏感膜片的挠度变化与膜厚、半径及施加压力的关系理论模型，并在此基础上进行了膜片的MATLAB二维数值仿真和Comsol Multiphysics三维数值仿真，并完成了FP压力敏感头的制作，进而设计了能够应用于光纤传感的解调方法，搭建了光纤传感的压力测试系统并进行了相关实验，利用所设计的解调方法对实验数据进行处理，进而对压力传感器的性能及特性进行了测试和验证。实验结果表明，传感器测试曲线线性度良好，与数值仿真结果基本一致，在100 kPa的量程范围内其灵敏度可达62.3 nm/kPa，温度敏感系数为0.023μm/℃，测量精度3.93%，且最小压强分辨率为1.29 kPa，证实了该MEMS光纤法珀压力传感系统具有一定的可行性。%A kind of MEMS optical fiber Fabry-Perot pressure sensor was proposed based on the pressure sensing principle which due to the change of cavity length caused by the deformation of sensitive diaphragm when pressure applied. The sensor’s theoretical model between sensitive diaphragm deflection variation with film thickness,radius and loading pressure was established. On the basis,the two-dimensional simulation using MATLAB and three-dimensional numerical simulation by Comsol Multiphysics software was performed and the processing fabrication of FP pressure sensing part was realized as well. Thus the demodulation method which can be applied to the optical fiber sensing was designed and related experiments were taken on after the implementation of optical fiber sensing pressure testing system. By employing the designed demodulation method,the sensor’s performance and characteristics can be tested and verified. The experimental results indicate that the linearity of sensor’s measured curve is good and broadly consistent with the results of numerical simulation,the sensitivity under 100 kPa is about 62.3 nm/kPa with a temperature sensitivity coefficient of 0.023μm/℃,the measured resolution and precision are 1.29 kPa and 3.93%respectively that confirmed the method of MEMS optical fiber pressure sensing system performs a potential possibility.