scholarly journals Paper-Based ZnS:Cu Alternating Current Electroluminescent Devices for Current Humidity Sensors with High–Linearity and Flexibility

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4607 ◽  
Author(s):  
Yaqin He ◽  
Mengyao Zhang ◽  
Nan Zhang ◽  
Danrong Zhu ◽  
Chun Huang ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Silver Nanowires ◽  
Alternating Current ◽  
Sensor Technology ◽  
Sensing Element ◽  
Humidity Sensors ◽  
Phosphor Layer ◽  
Humidity Sensing ◽  
Electroluminescent Devices ◽  
Sensing Mechanism

Humidity sensors are indispensable for various electronic systems and instrumentations. To develop a new humidity sensing mechanism is the key for the next generation of sensor technology. In this work, a novel flexible paper-based current humidity sensor is proposed. The developed alternating current electroluminescent devices (ACEL) consist of the electroless plating Ni on filter paper and silver nanowires (AgNWs) as the bottom and upper electrodes, and ZnS:Cu as the phosphor layer, respectively. The proposed humidity sensor is based on ACEL with the paper substrate and the ZnS:Cu phosphor layer as the humidity sensing element. The moisture effect on the optical properties of ACELs has been studied firstly. Then, the processing parameters of the paper-based ACELs such as electroless plated bottom electrode and spin-coated phosphor layer as a function of the humidity-sensitive characteristics are investigated. The sensing mechanism of the proposed sensor has been elucidated based on the Q ~ V analysis. The sensor exhibits an excellent linearity ( R 2 = 0.99965 ) within the humidity range from 20% to 90% relative humidity (RH) and shows excellent flexibility. We also demonstrate its potential application in postharvest preservation where the EL light is used for preservation and the humidity can be monitored simultaneously through the current.

Fabrication of bulk alumina structures with humidity sensing capabilities using direct ink write technique

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anabel Renteria ◽  
Luisa F. Garcia ◽  
Jorge A. Diaz ◽  
Luis C. Delfin ◽  
Jaime E. Regis ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Post Processing ◽  
Humidity Sensors ◽  
Moisture Sensitivity ◽  
Humidity Sensing ◽  
Content Type ◽  
Lattice Design ◽  
Processing Treatment ◽  
Binder Ratio ◽  
Order Of Magnitude

Purpose The purpose of this study is to evaluate different 3D structures for humidity sensing that will enable the fabrication of complex geometries with high moisture sensitivity. Design/methodology/approach Humidity sensors based on alumina ceramics were fabricated using direct ink write (DIW) technique. Different engineered surface area, polymer binder ratio and post-processing treatment were considered to increase moisture sensitivity. Findings It was found that the binder ratio plays an important role in controlling the rheology of the paste during printing and determining the pore size after post-processing treatment. The sensibility of the fabricated humidity sensor was investigated by measuring its capacitance response toward relative humidity (RH) varying from 40% to 90% RH at 25°C. It is shown that using 3D lattice design, printed alumina humidity sensor could improve sensitivity up to 31.6 pF/RH%, over an order of magnitude higher than solid alumina. Originality/value Most of the alumina humidity sensors available are films in nature because of manufacturing difficulties, which limited its potential of higher sensitivity, and thus broader applications. In this paper, a novel 3D alumina humidity sensor was fabricated using DIW 3D printing technology.

Highly chemoresistive humidity sensing using poly(ionic liquid)s

2016 ◽  
Vol 52 (54) ◽  
pp. 8417-8419 ◽  
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.

Humidity Sensor - A Review of Nanostructured Zinc Oxide (ZnO)-Based Humidity Sensor

2015 ◽  
Vol 1109 ◽  
pp. 395-400 ◽  
Author(s):  
A.S. Ismail ◽  
M.H. Mamat ◽  
Mohamad Rusop
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Humidity Sensor ◽  
Preparation Method ◽  
Low Cost ◽  
Sol Gel ◽  
Extreme Environment ◽  
Humidity Sensors ◽  
Humidity Sensing ◽  
Gel Preparation

We have reviewed humidity sensors based on the Zinc oxide (ZnO) humidity sensor. There are only a few papers reviewing on the ZnO humidity sensor. The characteristics, structures, advantages, and fabrication methods of ZnO have been studied to understand the suitability of the ZnO to be applied at different kind of condition such as for extreme environment, low level humidity detection, and very high humidity level circumstances. The electrical and physical properties of ZnO humidity sensors such as sensitivity, response time, stability, uniformity, and crystallinity have also been discussed in this review. ZnO nanostructures have been widely used for humidity sensors because of its’ good stability, high sensitivity for humidity-sensing, low cost, and has a wide band gap. Sol-gel preparation method is commonly used to for ZnO humidity sensor fabrication since it can produce a film with high uniformity, simple process and low cost. Keywords: Humidity Sensor, Metal Oxide, Semiconducting Type, Ceramic Type, Humidity-Sensing, Band Gap, Sol-Gel Preparation Method.

High-performance humidity sensors based on electrospinning ZnFe2O4 nanotubes

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68299-68304 ◽  
Author(s):  
Ming Zhuo ◽  
Ting Yang ◽  
Tao Fu ◽  
Qiuhong Li
Keyword(s):  
High Performance ◽  
Humidity Sensor ◽  
Hollow Structure ◽  
Electrical Measurements ◽  
Excellent Performance ◽  
Humidity Sensors ◽  
Humidity Sensing ◽  
Electrospinning Method

In this paper, ZnFe2O4 nanotubes with hollow structure were synthesized by a simple electrospinning method. Humidity sensor was fabricated based on these nanotubes. The electrical measurements show excellent performance in humidity sensing.

Controlled Zn1−xNixO nanostructures for an excellent humidity sensor and a plausible sensing mechanism

2018 ◽  
Vol 42 (11) ◽  
pp. 8445-8457 ◽  
Author(s):  
Alfa Sharma ◽  
Yogendra Kumar ◽  
Kushal Mazumder ◽  
Amit Kumar Rana ◽  
Parasharam M. Shirage
Keyword(s):  
Adsorption Isotherm ◽  
Humidity Sensor ◽  
Isotherm Model ◽  
Humidity Sensing ◽  
Sensing Mechanism ◽  
Freundlich Adsorption Isotherm

A Freundlich adsorption isotherm model confirms a plausible humidity sensing mechanism when using wet chemically prepared Zn1−xNixO nanostructures.

Humidity Sensing Behavior of Nano-Particle Size Magnesium Chromites Derived from the Tannery Wastewater

2020 ◽  
Vol 18 (2) ◽  
pp. 101-107
Author(s):  
A. S. Abdelmoaty ◽  
A. A. Hanna ◽  
S. M. Mousa ◽  
M. A. Sherief ◽  
W. A. Abd El-Ghany
Keyword(s):  
Humidity Sensor ◽  
Chromium Content ◽  
Tannery Wastewater ◽  
Crystalline Size ◽  
Nano Particle ◽  
Electrical Behavior ◽  
Humidity Sensors ◽  
Humidity Sensing ◽  
Calcination Temperatures ◽  
Sensor Device

The aim of this work is recovery the chromium content from the tannery wastewater to decrease the environmental pollution. Also, benefit the extracted chromium compound by study their electrical behavior to be used as humidity sensor device. The chromium content was extracted as a solid power by using MgO for precipitation. The prepared dry powder was characterized by different process. The results of the characterizations indicate that the chromium content precipitated as MgCr2O4. The efficiency of separation reaches to 99.98%. The crystalline size was calculated by applying Scherer equation, the calculation indicate that the MgCr2O4 formed in nano-sized particles and affected markedly with calcinations. As the calcination temperatures increase from 300 to 900 °C the crystalline size increases from 44.1 to 70.6 nm, this may due to growth the crystals by calcinations. To study the evaluation of MgCr2O4 as relative humidity (RH) sensors, the dried samples were exposed to different humidities between 22 to 92%. The electrical behaviors of humidity samples were measured to investigate the humidity sensing. AC conductivity of both the dry and the humidity samples indicate that the conductivity increases as the humidity increase from 27 to 80 RH%. The variation of conductivity for both dried and humidity samples shows that as the humidity increases from 22 to 80, the conductivity increases while above 80% the conductivity greatly increase. From the dependence of the electrical properties of MgCr2O4 on water content, it may conclude that, MgCr2O4 can be used as humidity sensors between 27 to 90%.

scholarly journals Humidity Sensor Based on Etched Optical Fibers Coated With Graphene Composite

2021 ◽  
Author(s):  
F. Ostovari ◽  
E. Owji ◽  
H. Mokhtari Iran
Keyword(s):  
Graphene Oxide ◽  
Relative Humidity ◽  
Silica Gel ◽  
Optical Fibers ◽  
Humidity Sensor ◽  
Coated Sample ◽  
Humidity Sensors ◽  
Humidity Sensing ◽  
Graphene Composite ◽  
One To One

Abstract In this research, optical humidity sensors based on etched-optical fibers coated with graphene Oxide (GO), silica gel (Sg) and a silica gel modified with GO (GSg) was studied. Their humidity sensing behavior was investigated by variation of relative differentiation of attenuation (RDA) in the presence of relative humidity (RH). As the results showed, etched fibers coated with Sg and GSg are highly capable of humidity sensing. However, a Sg- coated sample is not useful as humidity sensor related to sample coated by GSg because its RDA lacks a one-to-one correspondence with RH. As it was also found, the sensitivity of a GSg-coated sample is higher when the RH is below 40% and its repeatability is considerable.

scholarly journals Electrical and Humidity-Sensing Properties of Impedance-Type Humidity Sensors that Were Made of Ag Microwires/PPy/SnO2 Ternary Composites

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 92
Author(s):  
Pi-Guey Su ◽  
Ping-Hsiang Lu
Keyword(s):  
Composite Film ◽  
Humidity Sensor ◽  
Composite Films ◽  
Complex Impedance ◽  
Humidity Sensors ◽  
Ternary Composite ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Humidity Sensing Properties

Impedance-type humidity sensors were fabricated via one-step UV-irradiation photopolymerization of Ag microwires (Ag MWs), polypyrrole (PPy) and SnO2 ternary composite (Ag MWs/PPy/SnO2) films on an alumina substrate. X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX) elemental mapping were used to analyze the morphology, structure, and composition of Ag MWs/PPy/SnO2 ternary composite films. Microstructural observations revealed that the Ag MWs were embedded, and PPy formed on the surface of the Ag MWs/PPy/SnO2 ternary composite film. The effects of the addition amounts of loading of Ag and PPy on the electrical and humidity-sensing properties of the Ag MWs/PPy/SnO2 ternary composite films were investigated. The impedance-type humidity sensor based on Ag MWs/PPy/SnO2 ternary composite film containing 6 mg of Ag and 0.1 g of PPy had the highest sensitivity and an acceptable linearity over the RH ranged from 10% to 90% RH, a low hysteresis, a fast response time, and long-term stability. This technique is useful for practical application because its fast and ease of fabrication. The ions (H3O+) that dominate the impedance changed with relative humidity (RH) for the humidity sensor that based on Ag MWs/PPy/SnO2 ternary composite film was analyzed using complex impedance spectra.

scholarly journals Humidity Sensor - A Review of Nanostructured Zinc Oxide (ZnO) - Based Humidity Sensor

2015 ◽  
Vol 773-774 ◽  
pp. 706-710
Author(s):  
A.S. Ismail ◽  
M.H. Mamat ◽  
Mohamad Rusop
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Humidity Sensor ◽  
Preparation Method ◽  
Low Cost ◽  
Sol Gel ◽  
Extreme Environment ◽  
Humidity Sensors ◽  
Humidity Sensing ◽  
Gel Preparation

We have reviewed humidity sensors based on the Zinc oxide (ZnO) humidity sensor. There are only a few papers reviewing on the ZnO humidity sensor. The characteristics, structures, advantages, and fabrication methods of ZnO have been studied to understand the suitability of the ZnO to be applied at different kind of condition such as for extreme environment, low level humidity detection, and very high humidity level circumstances. The electrical and physical properties of ZnO humidity sensors such as sensitivity, response time, stability, uniformity, and crystallinity have also been discussed in this review. ZnO nanostructures have been widely used for humidity sensors because of its’ good stability, high sensitivity for humidity-sensing, low cost, and has a wide band gap. Sol-gel preparation method is commonly used to for ZnO humidity sensor fabrication since it can produce a film with high uniformity, simple process and low cost. Keywords: Humidity Sensor, Metal Oxide, Semiconducting Type, Ceramic Type, Humidity-Sensing, Band Gap, Sol-Gel Preparation Method.

scholarly journals Dual-mode humidity detection using a lanthanide-based metal–organic framework: towards multifunctional humidity sensors

2017 ◽  
Vol 53 (32) ◽  
pp. 4465-4468 ◽  
Author(s):  
Yuan Gao ◽  
Pengtao Jing ◽  
Ning Yan ◽  
Michiel Hilbers ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Humidity Sensor ◽  
Metal Organic Framework ◽  
Dual Mode ◽  
Humidity Sensors ◽  
Highly Effective ◽  
Metal Organic ◽  
Spectroscopy Studies ◽  
Organic Framework

Combined photoluminescence and impedance spectroscopy studies show that a europium-based metal–organic framework behaves as a highly effective and reliable humidity sensor, enabling dual-mode humidity detection.

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