Ethanol Gas Sensor Based on a Hybrid Polymethyl Methacrylate–Silica Microfiber Coupler

Ethanol Vapor Sensor Based on a Microfiber with Quantum- Dots Gel Coating

“…Both the ascending and descending test, the sensor showed good linear response and the hysteresis was very low. The ethanol sensitivity was calculated as -3.3%/ppm，which is three orders as high as the previous work, which is based on wavelength demodulation methods with relatively sensitivity of 6 -5 %/ppm [6]. It should be noted that the sensitivity can be further enhanced by means of decreasing the diameter of the microfiber, exploring an optimal QD doping concentration and even fabricating fiber gratings pair on both sides of the microfiber to form a resonant cavity.…”

“…Ethanol concentration is an important parameter in many applications from biomedicine to safety, even in our daily life, for example alcohol test for the drivers. Various of ethanol sensors have been proposed and developed based on different sensing principles, such as electric gas sensors [1][2], SAW gas sensors [3] and optical fiber gas sensors [4][5][6][7][8]. Among them, optical fiber sensors attract more attentions these years, due to their unique advantages of immune to electromagnetic interference, high sensitivity and compact size.…”

“…Similarly, optical fiber long period grating (LPG) with ZnO nanorod coating was also developed for ethanol vapor sensing [5]. Recently, an ethanol gas sensor based on a hybrid PMMA-silica microfiber coupler has been investigated and the experimental results show a linear sensitivity of 0.65 pm/ppm [6]. However, the demodulation scheme of these sensors is in the wavelength region, which always needs bulk equipment with high precise and high expense.…”

“…Especially, the FBG and microfiber coupler sensors, suffers really high temperature-cross sensitivity of 0.8%/℃ [4] and -1450 ppm/℃ [6], respectively. On the other hand, the principle of these sensors refer to electronic or structural changes that take place into the volume of the coating material [4,5,7] or sensing arm/film [6,8]. Due to the diffusion law, longer penetration time is required for inducing significant refractive index changes.…”

“…Due to the diffusion law, longer penetration time is required for inducing significant refractive index changes. Thus the response time of such sensors varies from ~10 s [6] to several minutes [4,5,7,8].…”