基于镀钯薄膜的微悬臂梁型光纤光栅氢传感器的设计和制备

Design and Fabrication of Micro-Cantilever Beam Fiber Bragg Grating Hydrogen Sensor Based on Coated-Palladium Film

利用微型机电系统(MEMS)加工工艺制备微悬臂梁,开发了一种由镀钯薄膜微悬臂梁和光纤布拉格光栅(FBG)组成的氢气敏光纤传感器,通过光栅波长的变化测量微悬臂梁吸收氢气时产生的位移,从而反映出环境中的氢浓度。应用弹性力学理论分析其工作原理,建立了传感器最大波长变化量与氢浓度关系的数学模型。结果表明,改变钯膜/硅悬臂梁厚度比可以提高传感器的灵敏度,厚度比为0.4时,传感器响应量最大。通过实验研究了传感器的氢响应特性,理论模型预测的最大波长变化量与实验结果十分吻合。

A novel micro cantilever-based hydrogen sensor with fiber Bragg grating（FBG） for detection of hydrogen was developed.The deflection of microcantilever due to absorption of hydrogen was measured by the wavelength shift of FBG,then,the content of hydrogen can be inferred.The stress transfer model of the sensor is analyzed based on elasticity theory.The relationship between the Bragg wavelength shift and the saturation hydrogen content is derived,and it shows that the sensitivity of the sensor can be improved by changing the thickness ratio of palladium and silicon cantilever beam and the maximum wavelength shift is obtained as thickness ratio is 0.4.The response of the sensor to hydrogen was measured.The analytical value was close to the experimental result.