基于PVDF压电膜片的光声探测器制备及应用

Fabrication and Application of Nonresonant Photoacoustic Detector Based on PVDF Diaphragm

非共振光声红外气体检测系统因其结构简单,成本低和检测灵敏度高的特点,具有较好的应用前景。该文提出了以聚偏氟乙烯(PVDF)压电膜片为微压敏感元件的非共振光声探测器,利用ANSYS对压电膜片进行了有限元分析,设计制备了双膜片结构微压敏感元件,其中PVDF压电膜片厚度为20μm,尺寸为10mm×5mm。设计了包含吸收腔和补偿腔的双腔室结构,并完成了光声探测器的封装。将光声探测器应用于非分光红外(NDIR)气体检测系统,探测器的输出信号与CO_2气体浓度有较好的线性关系,最低理论检测浓度约为29×10^(-6)。

Nonresonant photoacoustic gas detection system shows good expectation because of its simple structure,low cost and high sensitivity.A photoacoustic detector based on piezoelectric polyvinylidenefluoride（PVDF）diaphragm was proposed.The properties of PVDF diaphragm was analyzed with finite element approach using ANSYS.A double-layer structured micro-pressure sensor based on two pieces of PVDF diaphragms with opposite polarization orientations was designed and fabricated,and the size of the PVDF diaphragms is 10mm×5mm×20μm.The photoacoustic chamber consisting of an absorption chamber and a compensation chamber was designed and the encapsulation of the detector was completed.The CO2 gas sensing properties of the detector were investigated.The relationship between the response of the detector and the concentration of CO2 shows good linearity and the theoretical detection limit of CO2 is about 29×10^-6.