scholarly journals Nonporous Inorganic Nanoparticle-Based Humidity Sensor: Evaluation of Humidity Hysteresis and Response Time

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3858
Author(s):  
Shinya Kano ◽  
Harutaka Mekaru
Keyword(s):  
Response Time ◽  
Humidity Sensor ◽  
Silica Nanoparticle ◽  
Fast Response ◽  
Inorganic Nanoparticles ◽  
Humidity Sensors ◽  
Inorganic Nanoparticle ◽  
Response Recovery ◽  
Recovery Times ◽  
Nanoparticle Film

Fast-response humidity sensors using nanomaterials are attractive and have been intensively studied. Among the various nanomaterials, nonporous inorganic nanoparticles are suitable for use in humidity sensitive films for sensors. Here, we focus on a nonporous inorganic nanoparticle film and investigate a humidity sensor using the film. Hysteresis error and a dynamic response to a change of humidity are fundamental specifications of humidity sensors. A humidity sensor using a 50 nm silica nanoparticle film shows a hysteresis error of 2% at 85% RH and a response/recovery time of 2.8/2.3 s in 30% RH to 70% RH. We also summarize response/recovery times and hysteresis errors of state-of-the-art humidity sensors. As compared to those of commercial sensors and porous nanoparticle-based sensors evaluated using saturated salt solutions, the fabricated sensor shows a comparative hysteresis error and shorter response time.

Proton transport over nanoparticle surface in insulating nanoparticle film-based humidity sensor

2022 ◽  
Author(s):  
Shinya Kano ◽  
Harutaka MEKARU
Keyword(s):  
Activation Energy ◽  
Proton Transfer ◽  
Proton Transport ◽  
Humidity Sensor ◽  
Silica Nanoparticle ◽  
Humidity Sensors ◽  
Nanoparticle Surface ◽  
Transfer Mechanisms ◽  
Hydrophobic Ligand ◽  
Nanoparticle Film

Abstract We study a proton transport on the surface of insulating nanoparticles for humidity sensors. We use the approach to reveal proton transfer mechanisms in humidity sensitive materials. Hydrophilic and hydrophobic ligand-terminated silica nanoparticle films are adopted for evaluating temperature dependence of the ion conductivity. According to the activation energy of the conductivity, we explain the Grotthuss (H+ transfer) and vehicular (H3O+ transfer) mechanisms are mainly dominant on hydrophilic (-OH terminated) and hydrophobic (acrylate terminated) surface of nanoparticles, respectively. This investigation gives us a clue to understand a proton transfer mechanism in solution-processed humidity-sensitive materials such as oxide nanomaterials.

scholarly journals Low-Hysteresis and Fast Response Time Humidity Sensors Using Suspended Functionalized Carbon Nanotubes

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 680 ◽  
Author(s):  
Shivaram Arunachalam ◽  
Ricardo Izquierdo ◽  
Frederic Nabki
Keyword(s):  
Carbon Nanotubes ◽  
Response Time ◽  
Humidity Sensor ◽  
Fast Response ◽  
Hysteresis Curve ◽  
Humidity Sensors ◽  
Fold Reduction ◽  
Stable Performance ◽  
Suspended Structure ◽  
Temperature Surface

A humidity sensor using suspended carbon nanotubes (CNTs) was fabricated using a low-temperature surface micromachining process. The CNTs were functionalized with carboxylic acid groups that facilitated the interaction of water vapor with the CNTs. The humidity sensor showed a response time of 12 s and a recovery time of 47 s, along with superior hysteresis and stable performance. The hysteresis curve area of the suspended structure is 3.6, a 3.2-fold reduction in comparison to the non-suspended structure. A comparative study between suspended and non-suspended devices highlights the advantages of using a suspended architecture.

scholarly journals Humidity Sensors with Shielding Electrode Under Interdigitated Electrode

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 659 ◽  
Author(s):  
Hong Liu ◽  
Qi Wang ◽  
Wenjie Sheng ◽  
Xubo Wang ◽  
Kaidi Zhang ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Capacitive Sensors ◽  
Humidity Sensors ◽  
Interdigitated Electrode ◽  
Response Recovery ◽  
Chip Fabrication ◽  
Good Agreement ◽  
Capacitive Humidity Sensor

Recently, humidity sensors have been investigated extensively due to their broad applications in chip fabrication, health care, agriculture, amongst others. We propose a capacitive humidity sensor with a shielding electrode under the interdigitated electrode (SIDE) based on polyimide (PI). Thanks to the shielding electrode, this humidity sensor combines the high sensitivity of parallel plate capacitive sensors and the fast response of interdigitated electrode capacitive sensors. We use COMSOL Multiphysics to design and optimize the SIDE structure. The experimental data show very good agreement with the simulation. The sensitivity of the SIDE sensor is 0.0063% ± 0.0002% RH. Its response/recovery time is 20 s/22 s. The maximum capacitance drift under different relative humidity is 1.28% RH.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

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

Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6521-6525 ◽  
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.

scholarly journals Capacitive type Humidity Sensor based on PANI decorated Cu-Zns Porous Micropshere

2020 ◽  
Author(s):  
Jolly Bhadra ◽  
Hemalatha Parangusan ◽  
Zubair Ahmad ◽  
Shoaib Mallick ◽  
Farid Touati ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
In Situ Polymerization ◽  
Fast Response ◽  
Polymerization Process ◽  
Average Response ◽  
Surface Absorption ◽  
Absorption Properties ◽  
Recovery Times ◽  
Response And Recovery

PANI coated Cu-ZnS porous microsphere structures have been synthesized by hydrothermal method and in-situ polymerization process. The synthesized composite is characterized by different techniques in order to study the structural, morphological and surface absorption properties. The experimental observation demonstrates that the PANI/1%Cu-ZnS composite has better sensitivity, fast response and good stability as compared to pure PANI and other PANI/CuZnS compositions. Finally, PANI/1% Cu-ZnS composite has been found to be optimized for the humidity sensors due to its well-distributed roughness, porosity and hydrophilicity. The average response and recovery times of the PANI/1% Cu-ZnS are found to be 42 s and 24 s, respectively, which outperform recent results.

scholarly journals Evaluation of radiosonde humidity sensors at low temperature using ultralow-temperature humidity chamber

2018 ◽  
Vol 15 ◽  
pp. 207-212 ◽  
Author(s):  
Byung Il Choi ◽  
Sang-Wook Lee ◽  
Sang-Bong Woo ◽  
Jong Chul Kim ◽  
Yong-Gyoo Kim ◽  
...  
Keyword(s):  
Water Vapor ◽  
Low Temperature ◽  
Response Time ◽  
Humidity Sensor ◽  
Weather Prediction ◽  
Observation Data ◽  
Humidity Sensors ◽  
Ultralow Temperature ◽  
Humidity Chamber ◽  
Sensing Characteristics

Abstract. Accurate measurements of temperature and water vapor in the upper-air are of great interest in relation to weather prediction and climate change. Those measurements are mostly conducted using radiosondes equipped with a variety of sensors that are flown by a balloon up to lower stratosphere. Reference Upper Air Network (GRUAN) has identified water vapor pressure as one of the most important measurands and has set an accuracy requirement of 2 % in terms of the mixing ratio. In order to achieve the requirement, many errors in the humidity measurement such as a temperature dependency in sensing characteristics including measurement values and response time need to be corrected because humidity sensors of radiosondes pass through low-pressure (1 kPa) and low-temperature (−80 ∘C) environments in the upper-air. In this paper, the humidity sensing characteristics of Jinyang radiosonde sensors in relation to temperature dependencies were evaluated at low temperature using a newly developed ultralow-temperature humidity chamber. The sensitivity characteristic curve of the radiosonde sensors was evaluated down to −80 ∘C, and the calibration curves of the humidity sensor and the temperature sensor were obtained. The response time of humidity sensor slowly increased from 52 to 116 s at the temperature from 20 to −40 ∘C, respectively, and then rapidly increased to almost one hour at −80 ∘C. Those results will help to improve the reliability of the upper-air observation data.

Fast-response ionogel humidity sensor for real-time monitoring of breathing rate

2019 ◽  
Vol 3 (3) ◽  
pp. 484-491 ◽  
Author(s):  
Songhua Xiao ◽  
Jianxia Nie ◽  
Rou Tan ◽  
Xiaochuan Duan ◽  
Jianmin Ma ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Real Time ◽  
Humidity Sensor ◽  
Fast Response ◽  
Breathing Rate ◽  
Real Time Monitoring ◽  
Silica Network ◽  
Humidity Sensors ◽  
Human Breath

Ionogel-based chemoresistive humidity sensors have been successfully fabricated through ionothermal assembly of ionic liquids into a silica network, which exhibited superior humidity performances. Fast substantial impedance changes were observed with changing humidity for real-time monitoring of human breath.

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.

Using Palladium Nanocubes on ZnO Nanostructures in Hydrogen Gas Sensor for Fast Response and Recovery Time

2021 ◽  
Vol 21 (4) ◽  
pp. 2495-2499
Author(s):  
Hoang Si Hong ◽  
Tran Vinh Hoang
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Fast Response ◽  
Hydrogen Gas ◽  
Zno Nanostructures ◽  
Response Recovery ◽  
Sensor Structure ◽  
Recovery Times ◽  
Response And Recovery ◽  
Robust Sensing

We developed a novel sensor structure by synthesizing Pd nanocubes (NCs) decorated on ZnO nanostructures (NSs) applied to resistive-type H2 gas sensor with micro-length in sensing channel. The ZnO NSs were selectively grown between micro-size finger-like interdigital electrodes through microelectromechanical technology. The novel H2 sensor structure with the sensing channel was reduced to micro-size by this proposed method to obtain a sensor with fast response/recovery time. The as-prepared structure exhibited robust sensing performance with a response of 11% at optimal temperature of 150 °C, good linearity, and fast response/recovery time within 10 s. The speed of chemisorption through the diffusion pathway in Pd NCs combined with micro-length in sensing channel in sensor showed fast response and recovery times of 9 and 15 s, respectively, toward 10,000 ppm (1%) H2 at 150 °C. The result showed approximate linearity response in H2 concentration range of 5÷10,000 ppm and a large operating temperature range from room temperature to 200 °C.

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