Chitosan based fiber-optic Fabry–Perot humidity sensor

• Main Authors: Chen, Li Han, Li, Tao, Chan, Chi Chiu, Menon, R, Balamurali, Papusamy, Shaillender, Mutukumaraswamy, Neu, Björn, Ang, Xiu Min, Zu, Peng, Wong, Wei Chang, Leong, Kam Chew
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Chemical engineering
• Online Access: https://hdl.handle.net/10356/97806; http://hdl.handle.net/10220/12107
• Institution: Nanyang Technological University

A relative humidity fiber sensor based on Fabry–Perot interferometry configuration is presented. The proposed fiber sensor is functionalized with a thin layer of a moisture-sensitive natural polymer chitosan to form a low fineness Fabry–Perot sensor. The sensing scheme used in this work is based on the swelling effect of chitosan sensing film (degree of swelling varies as a function of relative humidity) which will induce optical path modulation when relative humidity is changed. As observed, the proposed sensor exhibits a sensitivity of 0.13 nm/%RH for relative humidity ranging from 20%RH to 95%RH with a RH uncertainty of ±1.68%RH and fast response time of 380 ms.