Single-Mode Modified Tapered Fiber Structure Functionalized With GO-PVA Composite Layer for Relative Humidity Sensing

Aneez Syuhada,Muhammad Safwan Abd Aziz,Ganesan Krishnan,Suzairi Daud,Muhammad Salleh Shamsudin,Sulaiman Wadi Harun

doi:10.1007/s13320-020-0595-0

Aneez Syuhada, Muhammad Safwan Abd Aziz + Show 4 more

Open Access

https://doi.org/10.1007/s13320-020-0595-0

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Abstract

A sensitive tapered optical fiber sensor incorporating graphene oxide (GO) and polyvinyl alcohol (PVA) composite film for the rapid measurement of changes in relative humidity was proposed and experimentally demonstrated. The sensing principle was based on the intensity modulation of the transmitted light induced by the refractive index changes of the sensitive coatings. The sensing region was obtained by tapering a section of single-mode optical fiber (SMF) from its original 125 µm diameter down to 9.03 µm. The tapered structure was then modified through deposition of GO/PVA nanocomposites by using the dip-coating technique. The field emission scanning electron microscope (FESEM) and Raman spectroscopy were used to characterize the structure of the composite film. As evidenced by a Fourier transform infrared spectroscopy (FTIR) analysis, the presence of oxygen functional groups (such as −OH and COOH) on the GO structure enabled the attachment of PVA molecules through hydrogen bonding and strong adhesion between GO/PVA layers. The performance of the sensor was tested over a wide range (20%RH to 99.9%RH) of relative humidity. The sensor showed a good response with its signal increasing linearly with the surrounding humidity. The tapered optical fiber sensor with the coating of GO/0.3g PVA achieved the highest sensitivity [0.5290RH (%)]. The stability, repeatability, reversibility, as well as response time of the designated sensor were also measured and analyzed.

Highlights

Knowledge in relative humidity (RH), the precise amount of water vapor in the air expressed as a percentage of the quantity needed for saturation at the same temperature, helps scientists in designing applications to satisfy human needs.Article type: RegularAneez SYUHADA et al.: Single-Mode Modified Tapered Fiber Structure Functionalized With graphene oxide (GO)-polyvinyl alcohol (PVA) CompositeLayer for Relative Humidity SensingMeasurements of RH are often expressed in percentage
We reported on the absorbance response of the tapered optical fiber coated with GO/PVA nanocomposites layer exposed with the humidity level ranging from 20% RH to 99.9% RH
The response of the tapered fiber coated with the GO/PVA composite film for RH sensing purpose was investigated

Summary

Introduction

Knowledge in relative humidity (RH), the precise amount of water vapor in the air expressed as a percentage of the quantity needed for saturation at the same temperature, helps scientists in designing applications to satisfy human needs.Article type: RegularAneez SYUHADA et al.: Single-Mode Modified Tapered Fiber Structure Functionalized With GO-PVA CompositeLayer for Relative Humidity SensingMeasurements of RH are often expressed in percentage. Knowledge in relative humidity (RH), the precise amount of water vapor in the air expressed as a percentage of the quantity needed for saturation at the same temperature, helps scientists in designing applications to satisfy human needs. Measurements of RH are often expressed in percentage. RH measuring sensors are used in agriculture, food processing, semiconductor processing, mining, textile, and pharmaceuticals industries. It is expected that the humidity sensor market will reach approximately USD 1.88 billion per annum by 2023 with a compound annual growth rate of 15% starting from 2017. Fiber-based sensing offers advantages over electrical and electronic sensing due to the predictable and controllable nature of the photonic behavior of the light

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