Composition-tuned lithium aluminosilicate as a new humidity-sensing ceramic material with high sensitivity

This paper reports on a nanocomposite synthesized by sol–gel procedure comprising graphene sheets with hollow spheres of titanium dioxide (G/HS-TiO2) with varying weight percentages of graphene for the purpose of humidity sensors. The surface morphology of the nanocomposite was characterized using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The structural properties were examined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The response to 12–80% RH at room temperature exhibited sensitivity (S = 135). However, the relative humidity range of 12–90% at room temperature exhibited higher sensitivity (S = 557). Sensors fabricated using the proposed nanocomposite exhibited high sensitivity to humidity, high stability, rapid response times, and rapid recovery times with hysteresis error of less than 1.79%. These results demonstrate the outstanding potential of his material for the monitoring of atmospheric humidity. This study also sought to elucidate the mechanisms underlying humidity sensing performance.

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Design of Conductive MWNTs/SiO2 Humidity Sensor Interface ASIC Based on AC Signals

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.562-565.344 ◽

2013 ◽

Vol 562-565 ◽

pp. 344-349

Author(s):

Tuo Li ◽

Xiao Wei Liu ◽

Liang Yin ◽

Chang Chun Dong

Keyword(s):

Humidity Sensor ◽

Work Group ◽

High Sensitivity ◽

Cmos Process ◽

Humidity Sensing ◽

Interface Circuit ◽

Testing Frequency ◽

Zero Offset ◽

Different Response ◽

Circuit Output

Previous research on MWNTs/SiO2 humidity sensing film by our work group has proved that MWNTs sensor has a different response mechanism to humidity at AC testing signals and shows greater testing stability and higher sensitivity, compared with traditional DC signal measurement. An interface circuit for conductive MWNTs/SiO2 humidity sensor is designed in this paper for humidity detection and prospection in miniaturization and integration. It aims at detecting the sensor’s humidity sensitive conductance signal at AC testing signals, and inhibiting the interference of capacitance signals. The ASIC demodulates the two signals by their phase difference and outputs a direct voltage proportional to conductance. The layout for ASIC is drawn by standard 0.5um P2M2 CMOS process and has a total area of 4*2mm2. In circuit level simulation by HSPICE which introduces practical data of the sensor’s humidity sensing characteristics, the relation of circuit output to conductance turns out to have great linearity at no more than 300 kHz and zero offset can be neglected at less than 100 kHz frequency. It is feasible to select proper testing frequency for high sensitivity and stability and make further investigations on the sensor’s frequency property.

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Highly chemoresistive humidity sensing using poly(ionic liquid)s

Chemical Communications ◽

10.1039/c6cc04056j ◽

2016 ◽

Vol 52 (54) ◽

pp. 8417-8419 ◽

Cited By ~ 26

Author(s):

Lingling Wang ◽

Xiaochuan Duan ◽

Wuyuan Xie ◽

Qiuhong Li ◽

Taihong Wang

Keyword(s):

Ionic Liquid ◽

Relative Humidity ◽

High Performance ◽

Humidity Sensor ◽

High Sensitivity ◽

Fast Response ◽

Humidity Sensors ◽

Humidity Sensing ◽

Good Repeatability ◽

Poly Ionic Liquid

A novel resistance type humidity sensor was fabricated using poly(ionic liquid)s, which exhibited high sensitivity, fast response, small hysteresis and good repeatability at a relative humidity (RH) in the range of 11–98%, making poly(ionic liquid)s as promising sensing materials for high-performance humidity sensors.

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High Sensitivity Optical Structures for Relative Humidity Sensing

Sensors for Everyday Life - Smart Sensors, Measurement and Instrumentation ◽

10.1007/978-3-319-47322-2_4 ◽

2016 ◽

pp. 55-79 ◽

Cited By ~ 1

Author(s):

Joaquin Ascorbe ◽

Jesus Corres ◽

Francisco J. Arregui ◽

Ignacio R. Matias ◽

Subhas Chandra Mukhopadhyay

Keyword(s):

Relative Humidity ◽

High Sensitivity ◽

Humidity Sensing

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The Effect of rGO-Doping on the Performance of SnO2/rGO Flexible Humidity Sensor

Nanomaterials ◽

10.3390/nano11123368 ◽

2021 ◽

Vol 11 (12) ◽

pp. 3368

Author(s):

Huangping Yan ◽

Zilu Chen ◽

Linyuan Zeng ◽

Zijun Wang ◽

Gaofeng Zheng ◽

...

Keyword(s):

Electron Microscopy ◽

High Performance ◽

Humidity Sensor ◽

High Sensitivity ◽

Polyimide Film ◽

Fast Response ◽

Humidity Sensing ◽

Transmission Electron ◽

Bending Radius ◽

New Applications

The development of a flexible and high-performance humidity sensor is essential to expand its new applications, such as personal health monitoring and early diagnosis. In this work, SnO2/rGO nanocomposites were prepared by one-step hydrothermal method. The effect of rGO-doping on humidity sensing performance was investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the nanostructure, morphology and chemical composition of SnO2/rGO nanocomposites. The SnO2/rGO humidity sensitive film was prepared by electrospinning on a polyimide film modified with gold electrodes. The humidity test results show that different doping ratios of rGO have different effects on humidity sensing properties. Among them, the sensor with 2 wt% rGO-doping has a high sensitivity (37,491.2%) within the humidity range as well as the fast response time (80 s) and recover time (4 s). Furthermore, the sensor with 2 wt% rGO-doping remains good flexibility and stability in the case of bending (1000 times). The sensitivity of the 2 wt% rGO-doping sensor at the bending radius (8 mm and 4 mm) is 48,219% and 91,898%, respectively. More importantly, the sensor could reflect different breathing states clearly and track breathing intervals as short as 3 s. The SnO2/rGO flexible humidity sensor with accuracy, flexibility and instantaneity as well as the facile fabrication strategy is conceivable to be applied in the potential application for human health real-time monitoring.

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A Compact Double-Folded Substrate Integrated Waveguide Re-Entrant Cavity for Highly Sensitive Humidity Sensing

Sensors ◽

10.3390/s19153308 ◽

2019 ◽

Vol 19 (15) ◽

pp. 3308 ◽

Cited By ~ 2

Author(s):

Zhihua Wei ◽

Jie Huang ◽

Jing Li ◽

Junshan Li ◽

Xuyang Liu ◽

...

Keyword(s):

Humidity Sensor ◽

High Sensitivity ◽

Substrate Integrated Waveguide ◽

Humidity Sensing ◽

Food Industries ◽

High Q ◽

Sensing Applications ◽

Compact Size ◽

Highly Sensitive ◽

Humidity Chamber

In this study, an ultra-compact humidity sensor based on a double-folded substrate integrated waveguide (SIW) re-entrant cavity was proposed and analyzed. By folding a circular re-entrant cavity twice along its two orthogonally symmetric planes, the designed structure achieved a remarkable size reduction (up to 85.9%) in comparison with a conventional TM010-mode circular SIW cavity. The operating principle of the humidity sensor is based on the resonant method, in other words, it utilizes the resonant properties of the sensor as signatures to detect the humidity condition of the ambient environment. To this end, a mathematical model quantitatively relating the resonant frequency of the sensor and the relative humidity (RH) level was established according to the cavity perturbation theory. The sensing performance of the sensor was experimentally validated in a RH range of 30%–80% by using a humidity chamber. The measured absolute sensitivity of the sensor was calculated to be 135.6 kHz/%RH, and the corresponding normalized sensitivity was 0.00627%/%RH. It was demonstrated that our proposed sensor not only has the merits of compact size and high sensitivity, but also benefits from a high Q-factor and ease of fabrication and integration. These advantages make it an excellent candidate for humidity sensing applications in various fields such as the agricultural, pharmaceutical, and food industries.

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Humidity sensing properties of SrTiO3 nanospheres with high sensitivity and rapid response

RSC Advances ◽

10.1039/c5ra00451a ◽

2015 ◽

Vol 5 (29) ◽

pp. 22879-22883 ◽

Cited By ~ 11

Author(s):

Dongmei Li ◽

Jingjing Zhang ◽

Liang Shen ◽

Wei Dong ◽

Caihui Feng ◽

...

Keyword(s):

High Sensitivity ◽

Rapid Response ◽

Humidity Sensing ◽

Sensing Properties ◽

Response And Recovery ◽

First Time ◽

Humidity Sensing Properties

SrTiO3 Nanospheres were employed for the first time to detect humidity and showed ultrafast response and recovery speeds.

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An In-Fiber Mach–Zehnder Interferometer Based on Arc-Induced Tapers for High Sensitivity Humidity Sensing

IEEE Sensors Journal ◽

10.1109/jsen.2013.2247591 ◽

2013 ◽

Vol 13 (5) ◽

pp. 2026-2031 ◽

Cited By ~ 26

Author(s):

Min Shao ◽

Xueguang Qiao ◽

Haiwei Fu ◽

Na Zhao ◽

Qinpeng Liu ◽

...

Keyword(s):

High Sensitivity ◽

Zehnder Interferometer ◽

Humidity Sensing ◽

Mach Zehnder Interferometer

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Humidity sensing properties of surface modified polyaniline ZnO nanocomposites

Sensor Review ◽

10.1108/sr-01-2015-0024 ◽

2015 ◽

Vol 35 (4) ◽

pp. 366-373 ◽

Cited By ~ 2

Author(s):

Omar Alhartomy

Keyword(s):

High Sensitivity ◽

Thermal Coefficient ◽

Humidity Sensing ◽

Content Type ◽

Food Industries ◽

Humidity Response ◽

Surface Modified ◽

Polymerization Method ◽

Domestic Purpose

Purpose – The aim of this study is to investigate the humidity-sensing of polyaniline–zinc oxide (PANI–ZnO) nanocomposites. Humidity sensor has wide applications in drug industries, food industries and domestic purpose to regulate the humidity level. Design/methodology/approach – PANI–ZnO composites were prepared by in situ polymerization method, and further humidity response was tested by using a two-probe sensor setup. Findings – PANI-ZnO composites surface were modified by using camphor sulphonic acid. DC conductivity is due to the hopping of polorans. Thermal coefficient value varies from 1.7 to 2.3. The 30 weight per cent composite shows high sensitivity among other composites. Research limitations/implications – These composites can be used only at room temperature or moderate temperature, i.e. below 280°C. Practical implications – The composites are prepared in tetrapod shape that has a large surface area and more stability. Therefore, these materials would be the replacement for conventional materials. Social implications – These sensors have many applications in food and drug preservation, domestic purposes, etc. Originality/value – This work is original, and not being considered for publication elsewhere. In this work, the charge transport properties were evaluated based on the resistivity change when samples were exposed to humidity.

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