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 micro-cantilever beam was fabricated by micro-electromechanical system (MEMS) processing technology. A hydrogen-sensitive fiber sensor consisting of palladium-coated film micro-cantilever and fiber Bragg grating (FBG) was developed. The micro-cantilever absorbs hydrogen When the displacement generated, thus reflecting the concentration of hydrogen in the environment. The principle of elasticity theory is used to analyze its working principle and a mathematical model of the relationship between the maximum wavelength variation of sensor and hydrogen concentration is established. The results show that the sensitivity of the sensor can be improved by changing the thickness ratio of palladium membrane / silicon cantilever. When the thickness ratio is 0.4, the sensor response is the largest. The hydrogen response characteristics of the sensor are experimentally studied. The maximum wavelength variation predicted by the theoretical model is in good agreement with the experimental results.