THE SENSING OF HUMIDITY BY SURFACE-TYPE Ag/FORMYL-TIPPCu(II)/Ag SENSOR FOR ENVIRONMENTAL MONITORING

2014 ◽  
Vol 21 (04) ◽  
pp. 1450048 ◽  
Author(s):  
DIL NAWAZ KHAN ◽  
MUHAMMAD HASSAN SAYYAD ◽  
MUHAMMAD TAHIR ◽  
FAZAL WAHAB ◽  
MUHAMMAD YASEEN ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Evaporation Process ◽  
Electrical Parameters ◽  
Humidity Sensors ◽  
Surface Type ◽  
Glass Substrates ◽  
Thermal Evaporator ◽  
Silver Electrodes ◽  
Hysteresis Response ◽  
Sublimation Technique

In this paper, we have studied the effects of changing relative humidity on the electrical parameters and their multi frequency response of the surface type Ag /formyl- TIPPCu ( II )/ Ag humidity sensors. The silver electrodes of thickness 100 nm were primarily deposited on cleaned glass substrates by thermal evaporator. A gap of 40 μm was created between the electrodes of each device by using mask during the evaporation process. Thin films of formyl- TIPPCu ( II ) of 140 nm thickness were grown on silver electrodes by thermal sublimation technique. The values of capacitance and resistance of the sensors were found at different humidity levels at frequency of 1, 10 and 100 kHz of AC input signal. A remarkable increase in capacitance and decrease in resistance were observed during the rise of relative humidity from 45% to 95% RH. The hysteresis response of these humidity sensors was also studied at 1 kHz AC signal.

scholarly journals PANI/MWCNT based humidity sensor

2019 ◽  
Vol 15 (33) ◽  
pp. 111-121
Author(s):  
Hammad R. Humud
Keyword(s):  
Relative Humidity ◽  
Humidity Sensor ◽  
Energy Gap ◽  
Low Frequency ◽  
Plasma Jet ◽  
Humidity Sensors ◽  
Surface Type ◽  
Weight Concentration ◽  
Nanocomposite Thin Films ◽  
Initial Capacity

Polyaniline Multi wall Carbon nanotube (PANI/MWCNTs) nanocomposite thin films have been prepared by Plasma jet polymerization at low frequency on glass substrate with preliminary deposited aluminum electrodes to form Al/PANI-MWCNT/Al surface-type capacitive humidity sensors, the gap between the electrodes about 50 μm and the MWCNTs weight concentration varied between 0, 1, 2, 3, 4%. The diameter of the MWCNTs was in the range of 8-15 nm and the length 10-55 μm. The capacitance-humidity relationships of the sensors were investigated at humidity levels from 35 to 90% RH. The electrical properties showed that the capacity increased with increasing relative humidity, and that the sensitivity of the sensor increases with the increase of the additive (MWCNTs); while each of the response time and the recovery time increasing with concentration. The change in MWCNTs concentration leads to a change in the energy gap as well as the initial capacity. The capacitance increases linearly with the relative humidity at MWCNTs concentration of 3% for thus the possibility of manufacturing humidity sensor with good specifications at this concentration.

scholarly journals Characterization and Comparison of Biodegradable Printed Capacitive Humidity Sensors

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6557
Author(s):  
Emma Wawrzynek ◽  
Carol Baumbauer ◽  
Ana Claudia Arias
Keyword(s):  
Relative Humidity ◽  
Potato Starch ◽  
Thermal Drift ◽  
Humidity Sensors ◽  
Interdigitated Electrode ◽  
Recovery Times ◽  
Environmental Relative Humidity ◽  
Response And Recovery ◽  
Silver Electrodes ◽  
The Relationship

Flexible and biodegradable sensors are advantageous for their versatility in a range of areas from smart packaging to agriculture. In this work, we characterize and compare the performance of interdigitated electrode (IDE) humidity sensors printed on different biodegradable substrates. In these IDE capacitive devices, the substrate acts as the sensing layer. The dielectric constant of the substrate increases as the material absorbs water from the atmosphere. Consequently, the capacitance across the electrodes is a function of environmental relative humidity. Here, the performance of polylactide (PLA), glossy paper, and potato starch as a sensing layer is compared to that of nonbiodegradable polyethylene terephthalate (PET). The capacitance across inkjet-printed silver electrodes is measured in environmental conditions ranging from 15 to 90% relative humidity. The sensitivity, response time, hysteresis, and temperature dependency are compared for the sensors. The relationship between humidity and capacitance across the sensors can be modeled by exponential growth with an R2 value of 0.99, with paper and starch sensors having the highest overall sensitivity. The PET and PLA sensors have response and recovery times under 5 min and limited hysteresis. However, the paper and starch sensors have response and recovery times closer to 20 min, with significant hysteresis around 100%. The PET and starch sensors are temperature independent, while the PLA and paper sensors display thermal drift that increases with temperature.

scholarly journals Role of nanostructured polymers on the improvement of electrical response-based relative humidity sensors

2016 ◽  
Vol 225 ◽  
pp. 96-108 ◽  
Author(s):  
I. Fratoddi ◽  
A. Bearzotti ◽  
I. Venditti ◽  
C. Cametti ◽  
M.V. Russo
Keyword(s):  
Relative Humidity ◽  
Electrical Response ◽  
Nanostructured Polymers ◽  
Humidity Sensors

scholarly journals Relative Humidity Sensors Based on Microfiber Knot Resonators—A Review

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5196 ◽  
Author(s):  
Young-Geun Han
Keyword(s):  
Relative Humidity ◽  
High Sensitivity ◽  
Physical Parameters ◽  
Humidity Sensors ◽  
Coating Materials ◽  
High Q ◽  
Sensing Applications ◽  
Compact Size ◽  
The Many ◽  
Humidity Sensitivity

Recent research and development progress of relative humidity sensors using microfiber knot resonators (MKRs) are reviewed by considering the physical parameters of the MKR and coating materials sensitive to improve the relative humidity sensitivity. The fabrication method of the MKR based on silica or polymer is briefly described. The many advantages of the MKR such as strong evanescent field, a high Q-factor, compact size, and high sensitivity can provide a great diversity of sensing applications. The relative humidity sensitivity of the MKR is enhanced by concerning the physical parameters of the MKR, including the waist or knot diameter, sensitive materials, and Vernier effect. Many techniques for depositing the sensitive materials on the MKR surface are discussed. The adsorption effects of water vapor molecules on variations in the resonant wavelength and the transmission output of the MKR are described regarding the materials sensitive to relative humidity. The sensing performance of the MKR-based relative humidity sensors is discussed, including sensitivity, resolution, and response time.

scholarly journals Chlorinated holey double-walled carbon nanotubes for relative humidity sensors

Carbon ◽  
2019 ◽  
Vol 148 ◽  
pp. 413-420 ◽  
Author(s):  
L.G. Bulusheva ◽  
V.I. Sysoev ◽  
E.V. Lobiak ◽  
Yu.V. Fedoseeva ◽  
A.A. Makarova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Relative Humidity ◽  
Humidity Sensors ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals Principles and Applications of Ceramic Humidity Sensors

1994 ◽  
Vol 16 (2) ◽  
pp. 69-87 ◽  
Author(s):  
Mario Pelino ◽  
Carlo Cantalini ◽  
Marco Faccio
Keyword(s):  
Impedance Spectroscopy ◽  
Relative Humidity ◽  
Response Time ◽  
State Of The Art ◽  
The State ◽  
Experimental Techniques ◽  
Humidity Sensors ◽  
Temperature Range ◽  
Si Doped ◽  
Signal Response

This paper presents a brief review of the state of the art in humidity and gas ceramic sensors R&D; it also describes the principle, fabrication and application of the humidity-sensitive Si-doped a-hematite (α-Fe2O3) sintered compacts. The humidity signal response is characterized by volt-amperometric and impedance spectroscopy techniques in the 0-97% relative humidity (RH) range. The response time of the sensor is evaluated by 0-60% RH variations. Experimental techniques used to measure the hysteresis, drift, and aging of the humidity setasor are presented and the results are discussed. The CO sensitivity is investigated by activating the sensor in the 350-450℃ temperature range. A humidity-meter prototype, based on the α-Fe2O3ceramic compact is described, and its electronics and features are presented in this paper.

Effect of Ceramsite Prewetting Degree on the Internal Relative Humidity of Ceramsite Concrete

2011 ◽  
Vol 94-96 ◽  
pp. 1451-1455
Author(s):  
Cai Yi Chen ◽  
Tao Ji ◽  
Yong Bo Chen ◽  
Yong Ning Liang
Keyword(s):  
Relative Humidity ◽  
Water Absorption ◽  
Pressure Measurement ◽  
Humidity Sensors ◽  
Measurement Device ◽  
Desorption Process ◽  
Reservoir Function ◽  
Internal Relative Humidity

The water absorption and desorption process of different prewetting degree ceramsites embedded in ceramsite concrete was obtained by a U-tube micro pressure measurement device. The internal relative humidities of ceramsite concrete using different prewetting degree ceramsites were monitored by humidity sensors. The study reveals that, with the increase of ceramsite prewetting degree, the internal relative humidity of ceramsite concrete increases because the reservoir function of ceramsite is more obvious.

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