Different morphologies of ZnO and their ethanol sensing property

This paper reports on the novel deposition of zinc oxide (ZnO) nanorods using dip pen nanolithographic (DPN) technique on SOI (silicon on insulator) CMOS MEMS (micro electro mechanical system) micro-hotplates (MHP) and their characaterisation as a low-cost, low-power ethanol sensor. The ZnO nanorods were synthesized hydrothermally and deposited on the MHP that comprises a tungsten micro-heater embedded in a dielectric membrane with gold interdigitated electrodes (IDEs) on top of an oxide passivation layer.The micro-heater and IDEs were used to heat up the sensing layer and measure its resistance, respectively. The sensor device is extremely power efficient because of the thin SOI membrane. The electro-thermal efficiency of the MHP was found to be 8.2°C/mW, which results in only 42.7 mW power at an operating temperature of 350°C. The CMOS MHP devices with ZnO nanorods were exposed to PPM levels of ethanol in humid air. The sensitivity achieved from the sensor was found to be 5.8%/ppm to 0.39%/ppm for the ethanol concentration range 25 -1000 ppm. The ZnO nanorods showed optimum response at 350°C.The CMOS sensor was found to have a humidity dependence that needs consideration in realworld application. The sensors were also found to be selective towards ethanol when tested in presence of toluene and acetone. We believe that the integration of ZnO nanorods using DPN lithography with a CMOS MEMS substrate offers a low cost, low power, smart ethanol sensor that could be exploited in consumer electronics.

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“…Hence the ZnO sensors are selective towards ethanol. This observation is also in agreement with other reported result on ethanol sensor 21 .…”

Section: Gas Responsesupporting

confidence: 94%

“…The obtained results (response, recovery and response time towards ethanol) are better than or comparable to the reported results available in literature 14,23,[32][33][34] . Some reports are also available which are better than our results 16,18,20,21 . It may be due to the different morphology and size of the nanostructures.…”

Section: Gas Responsesupporting

confidence: 38%

Dip pen nanolithography-deposited zinc oxide nanorods on a CMOS MEMS platform for ethanol sensing

et al. 2015

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“…A certain amount of C 2 H 5 OH gas was injected into the testing container through a syringe, such that the concentration of the gas in the container was 10, 20, 50, or 100 ppm. The ZnO-based sensor was used to detect the gas at these concentrations [17][18][19]. The response of the ZnO-based sensor with respect to the reducing gas, C 2 H 5 OH, was defined as Ra/Rg, where Ra and Rg were the resistances of the ZnO-based sensor in air and in the target gas, respectively.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of porous ZnO nanostructures using bamboo fibers as templates

Lian

et al. 2014

Materials Science-Poland

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In this study, we fabricated ZnO nanostructures using bamboo fibers as templates. The starting material used was zinc acetate, and the nanostructures were synthesized by soaking and calcining the bamboo fibers. The fabricated nanostructures were characterized using X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), and ultravioletvisible spectrophotometry. The results showed that the size of the ZnO nanoparticles was approximately 20 -100 nm. When the ZnO nanoparticles were used as the catalyst in the photodegradation of methyl orange, the dye degraded by 95.98 % in 80 min. The response and recovery times of a gas sensor based on the ZnO nanoparticles were 25 and 24 s, respectively, during the detection of C 2 H 5 OH in a concentration of 10 ppm at 270°C.

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“…Therefore, the development of a reliable and low-cost VOC sensor is highly necessary. Compared to conventional techniques, low-dimensional nanostructured ZnO due to the remarkable chemical, physical, and sensing properties [5][6][7] can be a good candidate to detect the VOCs [3,[8][9][10][11][12]. Many researchers have been reported the study of different volatile vapors sensing properties of nano-structured ZnO but it seems that there is a lack of detailed and more deeply study on VOCs sensing properties of nano-structured ZnO.…”

Section: Introductionmentioning

confidence: 99%

Investigation of sensitivity and selectivity of ZnO thin film to volatile organic compounds

2017

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This research addresses a detailed study on the sensitivity and selectivity of ZnO thin film to volatile organic compound (VOC) vapors that can be used for the development of VOC sensors. The ZnO thin film of 100 nm thickness was prepared by post-annealing of e-beam evaporated Zn thin film. The sample was structurally, morphologically, and chemically characterized by X-ray diffraction and field emission scanning electron microscopy analyses. The sensitivity, selectivity, and detection limit of the sample were tested with respect to a wide range of common VOC vapors, including acetone, formaldehyde, acetic acid, formic acid, acetylene, toluene, benzene, ethanol, methanol, and isopropanol in the temperature range of 200-400°C. The results show that the best sensitivity and detection limit of the sample are related to acetone vapor in the studied temperature range. The ZnO thin film-based acetone sensor also shows a good reproducibility and stability at the operating temperature of 280°C.

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Different morphologies of ZnO and their ethanol sensing property

Cited by 104 publications

References 38 publications

Dip pen nanolithography-deposited zinc oxide nanorods on a CMOS MEMS platform for ethanol sensing

Dip pen nanolithography-deposited zinc oxide nanorods on a CMOS MEMS platform for ethanol sensing

Synthesis of porous ZnO nanostructures using bamboo fibers as templates

Investigation of sensitivity and selectivity of ZnO thin film to volatile organic compounds

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