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Abstract

New plastic optical fibre sensors for detecting alcohol vapour have been studied. A certain kind of polymer such as a Novolac resin causes swelling when it is exposed to alcohol vapour. This effect produces a change in the polymer refractive index. Based on this principle, the plastic optical fibre (POF) type sensor head was fabricated by coating Novolac-resin and Novolac/Fe:SO complex film as a cladding layer on the plastic fibre core. When this sensor head was exposed to ethanol and methanol vapour, the light intensity passing through the sensor head changed remarkably depending on the vapour pressure. The sensor response was also found to be fast, stable and reproducible.

A plastic optical fibre sensor for real-time humidity monitoring

“…For example, the refractive index of hydroxyethylcellulose (HEC) film, which was measured using Abbe's refractometer, changed from 1.51 in the dry state to 1.48 in humid air with 80% RH, as shown in figure 1, by the closed circles. This property can be readily analysed using the one-dimensional diffusion equation and the relation between density and refractive index in a mixture [5]. The calculated refractive index of the HEC film after exposure to humid air is shown in figure 1 by the dashed line.…”

Amphiphilic diblock copolymer‐based multiagent photonic sensing scheme

“…The industrial use is further restricted due to long response times, or very expensive setups . Additionally, optical approaches have been exploited for ammonia sensing based on diffraction methods, or optical fibers, as for example, colorimetric changes of bromocresol purple, polyaniline, or a swelling resin . Moreover, block polymers have been employed for sensing applications.…”

“…10 Additionally, optical approaches have been exploited for ammonia sensing based on diffraction methods, 11,12 or optical fibers, as for example, colorimetric changes of bromocresol purple, 13 polyaniline, 14 or a swelling resin. 15 Moreover, block polymers have been employed for sensing applications. Recently, a real-time humidity sensor was developed by using a poly(styrenesulfonate-methylbutylene) (PSS-b-PMB) block copolymer with tailored hygroscopic properties where the deposition of the sensing material conducted in thin films and the detection method was based on changes of the reflected color signal.…”

Multi-hole plastic optical fiber force sensor based on femtosecond laser micromachining

“…The technology and applications of POF have progressed rapidly in recent years. A large number of sensors based on POF have been developed, such as breathing, alcohol, displacement, temperature, and refractive index sensors [1][2][3][4][5] . Optical fiber pressure sensor has the advantages of small volume, high measuring accuracy, and quick response, and has been widely studied.…”