An intrinsically stretchable humidity sensor based on anti-drying, self-healing and transparent organohydrogels

2019 ◽  
Vol 6 (3) ◽  
pp. 595-603 ◽  
Author(s):  
Jin Wu ◽  
Zixuan Wu ◽  
Huihua Xu ◽  
Qian Wu ◽  
Chuan Liu ◽  
...  

A facile solvent-exchange strategy is devised to fabricate anti-drying, self-healing and transparent organohydrogels for stretchable humidity sensing applications.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Rayyan Ali Shaukat ◽  
Qazi Muhammad Saqib ◽  
Mahesh Y. Chougale ◽  
...  

AbstractThis paper proposes a signal processed systematic 3 × 3 humidity sensor array with all range and highly linear humidity response based on different particles size composite inks and different interspaces of interdigital electrodes (IDEs). The fabricated sensors are patterned through a commercial inkjet printer and the composite of Methylene Blue and Graphene with three different particle sizes of bulk Graphene Flakes (BGF), Graphene Flakes (GF), and Graphene Quantum Dots (GQD), which are employed as an active layer using spin coating technique on three types of IDEs with different interspaces of 300, 200, and 100 µm. All range linear function (0–100% RH) is achieved by applying the linear combination method of nine sensors in the signal processing field, where weights for linear combination are required, which are estimated by the least square solution. The humidity sensing array shows a fast response time (Tres) of 0.2 s and recovery time (Trec) of 0.4 s. From the results, the proposed humidity sensor array opens a new gateway for a wide range of humidity sensing applications with a linear function.


2017 ◽  
Vol 10 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Chang-Ming Chen ◽  
Jun Xu

A passive evanescent mode half-mode substrate integrated waveguide (HMSIW) resonator loaded with a complementary split ring resonator (CSRR) is designed and fabricated for humidity sensing applications. The use of the CSRR which is etched on the top plane of the HMSIW can significantly reduce the size of the device. Without any sensing material, the sensor which has a compact size of 0.17λg × 0.17λg can provide high humidity sensitivity up to 5.82 MHz/%relative humidity (RH) at high RH region (>84.3%). The results indicate that the proposed structure is a promising candidate for radio and microwave humidity sensing applications.


Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3308 ◽  
Author(s):  
Zhihua Wei ◽  
Jie Huang ◽  
Jing Li ◽  
Junshan Li ◽  
Xuyang Liu ◽  
...  

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.


2020 ◽  
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Rayyan Ali Shaukat ◽  
Qazi Muhammad Saqib ◽  
Mahesh Chougale ◽  
...  

Abstract This paper proposes a signal processed systematic humidity sensor 3×3 array with all range and highly linear humidity response based on different particle size nanocomposite inks and different interspaces of interdigital electrodes (IDEs) (300, 200, and 100 µm). The fabricated sensors are patterned through a commercial inkjet printer by utilizing nanocomposites of methylene blue and graphene with three different particle sizes of bulk Graphene Flakes (BGF), Graphene Flakes (GF), and Graphene Quantum Dots (GQD), which are employed as an active layer on three types of IDEs with different interspaces of 300, 200, and 100 µm. From 3×3 sensor array, all range linear function (0-100% RH) is achieved by applying linear combination method of nine sensors in signal processing field, where weights for linear combination are required, which are estimated by the least square solution. The humidity sensing array shows a fast response time (Tres) of 0.2 sec and recovery time (Trec) of 0.4 sec. From the results, the proposed humidity sensor array opens a new gateway for a wide range of humidity sensing applications with a linear function.


RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19780-19786 ◽  
Author(s):  
Noshin Fatima ◽  
Fakhra Aziz ◽  
Zubair Ahmad ◽  
M. A. Najeeb ◽  
M. I. Azmeer ◽  
...  

This study exhibits a solution-processed organic semiconductor humidity sensor based on vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO), tris-(8-hydroxy-quinoline)aluminum (Alq3), and their composites.


RSC Advances ◽  
2018 ◽  
Vol 8 (18) ◽  
pp. 9963-9969 ◽  
Author(s):  
Zhe Wang ◽  
Min Xue ◽  
Herong Zhang ◽  
Zihui Meng ◽  
Kenneth J. Shea ◽  
...  

A simple and low-cost humidity sensor based on self-assembled three dimensional nanohydrogel colloidal array was prepared for humidity sensing.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anabel Renteria ◽  
Luisa F. Garcia ◽  
Jorge A. Diaz ◽  
Luis C. Delfin ◽  
Jaime E. Regis ◽  
...  

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.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5469
Author(s):  
Xiuxiu Xu ◽  
Mingming Luo ◽  
Jianfei Liu ◽  
Nannan Luan

We propose and demonstrate a temperature and humidity sensor based on a fluorinated polyimide film and fiber Bragg grating. Moisture-induced film expansion or contraction causes an extra strain, which is transferred to the fiber Bragg grating and leads to a humidity-dependent wavelength shift. The hydrophobic fluoride doping in the polyimide film helps to restrain its humidity hysteresis and provides a short moisture breathing time less than 2 min. Additionally, another cascaded fiber Bragg grating is used to exclude its thermal crosstalk, with a temperature accuracy of ±0.5 °C. Experimental monitoring over 9000 min revealed a considerable humidity accuracy better than ±3% relative humidity, due to the sensitized separate film-grating structure. The passive and electromagnetic immune sensor proved itself in field tests and could have sensing applications in the electro-sensitive storage of fuel, explosives, and chemicals.


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