Compact fiber Fabry–Perot sensors filled with PNIPAM hydrogel for highly sensitive relative humidity measurement

Xia, Ru-Lei, Liu, Juan, Shi, Jiulin, He, Xing-Dao, Yuan, Jinhui, Pike, Andrew R., Chu, Liang, Wu, Qiang and Liu, Bin (2022) Compact fiber Fabry–Perot sensors filled with PNIPAM hydrogel for highly sensitive relative humidity measurement. Measurement, 201. p. 111781. ISSN 0263-2241

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A fiber-optic Fabry–Perot (FP) based relative humidity (RH) sensor was proposed and experimentally investigated by using Poly(N-isopropylacrylamide) (PNIPAM) hydrogel to connect two ends of single-mode optical fiber to formulate a PNIPAM FP cavity. The water vapor will be absorbed by the PNIPAM hydrogel, which will alter both the refractive index (RI) and dimension of the PNIPAM FP cavity, resulting in the change of output resonance intensity in the reflective spectrum. The measure RH sensitivity is 1.634 nm/%RH within RH range from 45-75% with good linearity of 0.9897 and excellent repeatability. The influence of PNIPAM hydrogel concentration on the RH sensitivity has been investigated - the higher the concentration of PNIPAM hydrogel, the higher the RH sensitivity of the sensor. The developed sensor can effectively monitor human respiratory with response and recovery time of 0.91 s and 1.91 s, respectively.

Item Type: Article
Additional Information: Funding information: This work was jointly supported by the Natural Science Foundation of Jiangxi Province (20212BAB202024), National Natural Science Foundation of China (NSFC) (11864025, 62163029, 62175097 and 62065013). Nanchang Hangkong University graduate student innovation special fund project (Grant No. YC2021-074).
Uncontrolled Keywords: fiber-optic sensor, PNIPAM hydrogel, Fabry-Perot interferometer (FPI), Relative humidity (RH)
Subjects: F200 Materials Science
F300 Physics
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: John Coen
Date Deposited: 24 Aug 2022 10:12
Last Modified: 24 Aug 2022 10:15

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