High-performance humidity sensors based on electrospinning ZnFe2O4 nanotubes

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.

Download Full-text

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.

Download Full-text

High-performance humidity sensors from Ni(SO4)0.3(OH)1.4 nanobelts

Nanoscale ◽

10.1039/c4nr00277f ◽

2014 ◽

Vol 6 (12) ◽

pp. 6521-6525 ◽

Cited By ~ 7

Author(s):

Ming Zhuo ◽

Yuejiao Chen ◽

Tao Fu ◽

Haonan Zhang ◽

Zhi Xu ◽

...

Keyword(s):

High Performance ◽

Humidity Sensor ◽

High Sensitivity ◽

Fast Response ◽

Humidity Sensors ◽

Term Stability ◽

Long Term Stability

Ni(SO4)0.3(OH)1.4 nanobelts are utilized in a humidity sensor by a facile method. The nanobelt based sensor shows a high sensitivity, fast response and long-term stability in the sensing process.

Download Full-text

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

Rapid Prototyping Journal ◽

10.1108/rpj-12-2019-0322 ◽

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.

Download Full-text

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

Sensors ◽

10.3390/s19214607 ◽

2019 ◽

Vol 19 (21) ◽

pp. 4607 ◽

Cited By ~ 3

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.

Download Full-text

Humidity sensors based on graphene/SnOx/CF nanocomposites

Journal of Materials Chemistry C ◽

10.1039/c4tc00440j ◽

2014 ◽

Vol 2 (24) ◽

pp. 4861-4866 ◽

Cited By ~ 18

Author(s):

Tao Fu ◽

Jian Zhu ◽

Ming Zhuo ◽

Bingkun Guan ◽

Jidong Li ◽

...

Keyword(s):

High Performance ◽

Humidity Sensor ◽

Humidity Sensors

A high performance humidity sensor with the advantages of both graphene and SnOx/CFs.

Download Full-text

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.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1109.395 ◽

2015 ◽

Vol 1109 ◽

pp. 395-400 ◽

Cited By ~ 2

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.

Download Full-text

Development of La3+Doped CeO2Thick Film Humidity Sensors

Abstract and Applied Analysis ◽

10.1155/2014/297632 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Chunjie Wang ◽

Aihua Zhang ◽

Hamid Reza Karimi

Keyword(s):

Relative Humidity ◽

High Performance ◽

Humidity Sensor ◽

Humidity Sensors ◽

Response Recovery ◽

Relative Humidity Range ◽

Response And Recovery ◽

Sensitive Characteristics ◽

Humidity Range ◽

Maximum Humidity

The humidity sensitive characteristics of the sensor fabricated from 10 mol% La2O3doped CeO2nanopowders with particle size 17.26 nm synthesized via hydrothermal method were investigated at different frequencies. It was found that the sensor shows high humidity sensitivity, rapid response-recovery characteristics, and narrow hysteresis loop at 100 Hz in the relative humidity range from 11% to 95%. The impedance of the sensor decreases by about five orders of magnitude as relative humidity increases. The maximum humidity hysteresis is about 6% RH, and the response and recovery time is 12 and 13 s, respectively. These results indicate that the nanosized La2O3doped CeO2powder has potential application as high-performance humidity sensor.

Download Full-text

Effects of pH on High-Performance ZnO Resistive Humidity Sensors Using One-Step Synthesis

Sensors ◽

10.3390/s19235267 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5267 ◽

Cited By ~ 2

Author(s):

Yu ◽

Zhang ◽

Keyword(s):

High Performance ◽

Oxygen Vacancies ◽

Humidity Sensor ◽

Ph Value ◽

Precursor Solution ◽

Hydroxyl Group ◽

Water Molecules ◽

Hydroxyl Groups ◽

Humidity Sensors ◽

One Step

In this paper, we prepared a high-performance zinc oxide (ZnO) humidity sensor in an alkaline environment using one-step hydrothermal method. Experiments showed that the pH value of the precursor solution affects the performance of ZnO humidity sensors. There are abundant hydroxyl group and oxygen vacancies on the surface of ZnO with a precursor pH value of 10. Abundant hydroxyl groups on the surface of ZnO can adsorb a large number of water molecules and rich oxygen vacancies can accelerate the decomposition of water molecules, thus increasing the number of conductive ions (H3O+) and further improving the performance of the sensor. So, such a ZnO humidity sensor exhibited high sensitivity (14,415), good linearity, small hysteresis (0.9%), fast response/recovery time (31/15 s) in the range from 11% to 95% relative humidity (RH). Moreover, the ZnO-2 humidity sensor has good repeatability and can be effectively used for a long time. This study provides a new idea for the development of low-cost, high-performance and reusable ZnO resistive humidity sensors.

Download Full-text