A ZnO Nanoparticle-Coated Long Period Fiber Grating as a Carbon Dioxide Gas Sensor

Abstract

This study proposes a long period fiber grating (LPFG) with a zinc oxide (ZnO) nanoparticle layer for use as a carbon dioxide (CO 2) gas sensor. Inductively coupled plasma (ICP) etching, corona treatment, and electrostatic spraying were used to fabricate this ZnO nanoparticle-coated LPFG CO 2 gas sensor. Repeated gas sensor tests showed that, when a 15% CO 2 mixture was injected (0.2 L/min) into a closed chamber into which the sensor had been placed, the CO 2 gas was absorbed by the ZnO nanoparticle-coated LPFG sensor. In these tests, the transmission loss gradually decreased, and the maximum transmission loss was 2.039 dB. The concentration test results showed that as the concentration of CO 2 introduced into the chamber was increased, the rate of the transmission loss change was increased in direct proportion. In addition, the sensitivity was 0.0513 dB/%. The results confirm that this low-cost ZnO nanoparticle-coated LPFG gas sensor was successfully applied to the measurement of CO 2 gas. Therefore, the proposed ZnO nanoparticle-coated LPFG can be used to measure CO 2 gas.

Recent Advances in Fiber-Optic Sensors for the Detection of Inorganic Acidic Gases

“…When exposed to an environment with a CO 2 concentration of 15%, the response time of the sensor was approximately 13 min, accompanied by a transmission loss variation of about -2.884 dB (from -11.269 dB to -14.153 dB). To increase the response speed of the sensor, Wu et al [128] created a ZnO nanoparticle-coated CO 2 LPFG sensor, resulting in the improved adsorption efficiency and reduced response time of 6 min.…”

Tilted Fiber Bragg Grating Sensor with Graphene Oxide Coating for Humidity Sensing

“…Furthermore, fiber optic sensors for biomedical and home security purposes have also been developed in recent years. The mechanism by which such sensors provide measurements is very dependent on changes in the refractive index, such as in the case of LPG gas sensor measurements of CO 2 [ 1 ] and U-shaped bending-induced interference sensor measurements of glucose solutions [ 2 ]. However, these previously developed sensing methods have not taken into account the impact of environmental humidity.…”