A Rapid-Response, High-Sensitivity Nanophase Humidity Sensor for Respiratory Monitoring

2004 ◽  
Vol 25 (8) ◽  
pp. 526-528 ◽  
Author(s):  
A.K. Kalkan ◽  
H. Li ◽  
C.J. O'Brien ◽  
S.J. Fonash
RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1543-1552
Author(s):  
Yutong Yang ◽  
Guoting Su ◽  
Qilin Li ◽  
Zipiao Zhu ◽  
Shaoran Liu ◽  
...  

This work presents a nanocellulose-based humidity sensor with high sensitivity, remarkable reproducibility and rapid response/recovery behavior fabricated via freeze drying.


2020 ◽  
Author(s):  
Yuye Zhang ◽  
Yongxiu Song ◽  
Hong Yang ◽  
Kaiyang Chen ◽  
Qing Zhou ◽  
...  

Developing humidity sensing materials with fast response and high sensitivity was of great interest for many applications from industrial field to human healthcare. Here, we report a carbon nitride nanoribbons (CNNRs)-based humidity sensor. Thanks to the delicate humidity-responsive anisotropic deformation and well-balanced hydrophilic surfaces/hydrophobic framework with rapid adsorption/desorption of water molecules by CNNRs, this humidity sensor possessed an ultrafast response of ca. 50 ms, high reproducibility and selectivity, and linearity in an almost full humidity range. As an example, this sensor was successfully applied to real-time breathing detection, and the as-obtained breathing graphic waveforms exhibited a higher sensitivity than that by the traditional clinic measurements. This work would pave a new way for ultrafast and sensitive humidity sensing by using anisotropic deformation of CNNRs and introduce a new application scheme of humidity sensors in more user-friendly respiratory monitoring with higher resolution.<br>


2020 ◽  
Author(s):  
Yuye Zhang ◽  
Yongxiu Song ◽  
Hong Yang ◽  
Kaiyang Chen ◽  
Qing Zhou ◽  
...  

Developing humidity sensing materials with fast response and high sensitivity was of great interest for many applications from industrial field to human healthcare. Here, we report a carbon nitride nanoribbons (CNNRs)-based humidity sensor. Thanks to the delicate humidity-responsive anisotropic deformation and well-balanced hydrophilic surfaces/hydrophobic framework with rapid adsorption/desorption of water molecules by CNNRs, this humidity sensor possessed an ultrafast response of ca. 50 ms, high reproducibility and selectivity, and linearity in an almost full humidity range. As an example, this sensor was successfully applied to real-time breathing detection, and the as-obtained breathing graphic waveforms exhibited a higher sensitivity than that by the traditional clinic measurements. This work would pave a new way for ultrafast and sensitive humidity sensing by using anisotropic deformation of CNNRs and introduce a new application scheme of humidity sensors in more user-friendly respiratory monitoring with higher resolution.<br>


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1915
Author(s):  
Shenawar Ali Khan ◽  
Muhammad Saqib ◽  
Muhammad Muqeet Rehman ◽  
Hafiz Mohammad Mutee Ur Rehman ◽  
Sheik Abdur Rahman ◽  
...  

A novel composite based on a polymer (P(VDF-TrFE)) and a two-dimensional material (graphene flower) was proposed as the active layer of an interdigitated electrode (IDEs) based humidity sensor. Silver (Ag) IDEs were screen printed on a flexible polyethylene terephthalate (PET) substrate followed by spin coating the active layer of P(VDF-TrFE)/graphene flower on its surface. It was observed that this sensor responds to a wide relative humidity range (RH%) of 8–98% with a fast response and recovery time of 0.8 s and 2.5 s for the capacitance, respectively. The fabricated sensor displayed an inversely proportional response between capacitance and RH%, while a directly proportional relationship was observed between its impedance and RH%. P(VDF-TrFE)/graphene flower-based flexible humidity sensor exhibited high sensitivity with an average change of capacitance as 0.0558 pF/RH%. Stability of obtained results was monitored for two weeks without any considerable change in the original values, signifying its high reliability. Various chemical, morphological, and electrical characterizations were performed to comprehensively study the humidity-sensing behavior of this advanced composite. The fabricated sensor was successfully used for the applications of health monitoring and measuring the water content in the environment.


2013 ◽  
Vol 5 (12) ◽  
pp. 5825-5831 ◽  
Author(s):  
Ke Wang ◽  
Xuemin Qian ◽  
Liang Zhang ◽  
Yongjun Li ◽  
Huibiao Liu

2018 ◽  
Vol 32 (16) ◽  
pp. 1850199 ◽  
Author(s):  
Degao Lan ◽  
Xiaofeng Zhao ◽  
Fei Wang ◽  
Chunpeng Ai ◽  
Dianzhong Wen ◽  
...  

The humidity sensor based on silicon substrate is presented in this paper, which consists of anodic aluminum oxide (AAO) film and interdigitated electrodes. By using electro-chemical oxidizing technique, AAO film with high porosity is fabricated on the silicon substrate. Under optimal oxidization condition, pore diameter of 37–79 nm and depth about [Formula: see text]m is achieved. Interdigitated electrodes are fabricated on the top of AAO film by vacuum evaporation deposition method. The results show that the sensor has different nonlinear response in whole range of relative humidity (RH). Moreover, it has almost linear relationship between the capacitance and RH at high RH from 75% to 95%. The highest sensitivity is obtained 613 pF/%RH at 1 kHz, which is much higher than other frequencies.


2015 ◽  
Vol 645-646 ◽  
pp. 1298-1302
Author(s):  
Rui Zhao ◽  
Yong Zheng Wen ◽  
Wei Ma ◽  
Jian Cheng Yang ◽  
Xiao Mei Yu

In this paper, an aptasensor with high sensitivity and rapid response was developed for the detection of staphylococcus enterotoxin B (SEB) by using thiol-modified piezoresistive cantilever. Thiol-modified aptamers, acting as the functionalized sensing elements, were immobilized on the nanogold-coated surface of the sensing cantilever as agents for detecting SEB. By using the functionalized aptasensors, different concentrations of SEB were detected with a wide detection range of 6-100 ng/mL and a quick response in milk. The experimental results indicated that the cantilever-based aptasensors had sufficient sensitivity for the detection of SEB in real food commodities and might provide an economical platform for on-site detections of different toxicants with the advantages of portability, high sensitivity, and rapid response.


Sign in / Sign up

Export Citation Format

Share Document