Polymer-Dispersed Liquid Crystal Gas Sensor for Acetone Detection Using Correlated Laser Speckles  

作　　者：Xiaoquan BAI Ning BU Yuxiang YAN Yifei MA Mei WANG Suotang JIA Xuyuan CHEN Zhaomin TONG 

机构地区：[1]State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China [2]Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China

出　　处：《Photonic Sensors》2025年第1期189-199,共11页光子传感器(英文版)

基　　金：supported by the Key Research and Development Program of Shanxi Province,China(Grant No.202102030201002);the Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(Grant No.IRT_17R70);the State Key Program of National Natural Science of China(Grant No.11434007);the 111 Project,China(Grant No.D18001);the Fund for Shanxi“1331 Project”Key Subjects Construction,China.

摘　　要：Acetone is a widely used volatile organic compound in various industries,and several gas sensors have been developed for its detection and real-time monitoring.This study reported a novel method for determining the acetone vapor concentration based on correlated laser speckles using polymer-dispersed liquid crystals(PDLCs).Here,PDLC films comprising a mixture of the thermotropic nematic liquid crystal(LC)and ultraviolet-curable polymers were fabricated using different LC mass ratios and ultraviolet curing conditions.The laser beam was transmitted through the PDLC film to generate scattered light and speckles.When the PDLC film was exposed to the acetone vapor,the acetone molecules diffused into the PDLC film and interacted with the LC molecules,modifying the orientation of the LC molecules and the equivalent refractive index of the LC droplets.This in turn decreased the correlation coefficient of the speckle images.The experimental results indicated that the PDLC gas sensor was selectively sensitive to different concentrations of the acetone vapor,ranging from 1800 ppm to 3200 ppm.In comparison with traditional LC gas sensors that use a polarizing microscope to detect the change in brightness of the modulated light field,the proposed method is simpler,less expensive,and more robust under external disturbances such as vibrations.

关 键 词：Correlation laser speckle polymer dispersed liquid crystal(PDLC) liquid crystal droplet sizes ACETONE gas detection 

分 类 号：O436[机械工程—光学工程]