A highly sensitive humidity sensor based on an aggregation-induced emission luminogen-appended hygroscopic polymer microresonator

2021 ◽  
Author(s):  
Airong Qiagedeer ◽  
Hiroshi Yamagishi ◽  
Minami Sakamoto ◽  
Hanako Hasebe ◽  
Fumitaka Ishiwari ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
High Sensitivity ◽  
Aggregation Induced Emission ◽  
Highly Sensitive ◽  
Self Assembled

A self-assembled microsphere resonator, comprising a hygroscopic polymer with aggregation-induced emission luminogen pendants, can sense humidity with high sensitivity and repeatability.

scholarly journals A Compact Double-Folded Substrate Integrated Waveguide Re-Entrant Cavity for Highly Sensitive Humidity Sensing

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3308 ◽  
Author(s):  
Zhihua Wei ◽  
Jie Huang ◽  
Jing Li ◽  
Junshan Li ◽  
Xuyang Liu ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
High Sensitivity ◽  
Substrate Integrated Waveguide ◽  
Humidity Sensing ◽  
Food Industries ◽  
High Q ◽  
Sensing Applications ◽  
Compact Size ◽  
Highly Sensitive ◽  
Humidity Chamber

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.

Synthesized of Highly Sensitive Tin (IV)-Doped Zinc Oxide Humidity Sensor

2015 ◽  
Vol 1109 ◽  
pp. 559-563
Author(s):  
Ahmad Syakirin Ismail ◽  
Mohd Firdaus Malek ◽  
Muhammad Amir Ridhwan Abdullah ◽  
Mohamad Hafiz Mamat ◽  
M. Rusop
Keyword(s):  
Zinc Oxide ◽  
Recovery Time ◽  
Humidity Sensor ◽  
Sol Gel ◽  
High Sensitivity ◽  
Average Diameter ◽  
Undoped Sample ◽  
Immersion Method ◽  
Response Recovery ◽  
Highly Sensitive

High sensitivity Tin (IV) (Sn) - doped zinc oxide (ZnO) humidity sensor was deposited using sol-gel immersion method. The Sn-doped sample was deposited on glass substrate and undoped sample was also prepared to seem the improvement made through doping process. The analyses showed that the sensor’s morphology has become more porous and having lower average diameter of nanorods, high conductivity and higher response, recovery time, and sensitivity. The sensitivity of the sensor increased from 2 to 4 by doping with Sn.

scholarly journals Performance of the highly sensitive humidity sensor constructed with nanofibrillated cellulose/graphene oxide/polydimethylsiloxane aerogel via freeze drying

RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1543-1552
Author(s):  
Yutong Yang ◽  
Guoting Su ◽  
Qilin Li ◽  
Zipiao Zhu ◽  
Shaoran Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Freeze Drying ◽  
Humidity Sensor ◽  
High Sensitivity ◽  
Nanofibrillated Cellulose ◽  
Rapid Response ◽  
Response Recovery ◽  
Highly Sensitive ◽  
Recovery Behavior

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

scholarly journals High-Sensitivity Whispering Gallery Mode Humidity Sensor Based on Glycerol Microdroplet Volumetric Expansion

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1746
Author(s):  
Pauls Kristaps Reinis ◽  
Lase Milgrave ◽  
Kristians Draguns ◽  
Inga Brice ◽  
Janis Alnis ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Free Space ◽  
Humidity Sensor ◽  
Low Cost ◽  
High Sensitivity ◽  
Whispering Gallery Mode ◽  
Whispering Gallery ◽  
Volumetric Expansion ◽  
Highly Sensitive ◽  
Good Repeatability

We demonstrate a highly sensitive whispering gallery mode (WGM) relative humidity (RH) sensor based on a glycerol microdroplet. WGMs were excited using a 760 nm tunable semiconductor laser. We used free space coupling, which is effective when using a liquid resonator. A detailed analysis of different parameters influencing the sensor’s characteristics (sensitivity, hysteresis, resolution, stability, and temperature) is presented. The sensitivity of the sensor is one of the highest reported (2.85 nm/% RH in the range 50–70% RH with the resolution 1 × 10−4% RH). This type of humidity sensor has several advantages, such as high sensitivity, extended lifetime, good repeatability, and low cost, as well as the use of a non-toxic and environmentally friendly liquid.

Self-Assembled Polymer Thin Films Towards Nanoarchitectonics for Respiration Monitoring

2020 ◽  
Vol 20 (5) ◽  
pp. 2893-2901
Author(s):  
Premkumar Jayaraman ◽  
Chinnasamy Sengottaiyan ◽  
Karthik Krishnan
Keyword(s):  
Thin Films ◽  
Morphological Analysis ◽  
Humidity Sensor ◽  
Polymer Thin Films ◽  
Respiration Monitoring ◽  
Response Recovery ◽  
Human Respiration ◽  
Highly Sensitive ◽  
Transport Path ◽  
Self Assembled

Manipulation of ionic transport in the self-assembled polymer thin films using nanoarchitectonics approach can open the door for the development of novel electronic devices with ultrafast operation and low-power consumption. Here, we demonstrate a highly sensitive and ultrafast responsive flexible humidity sensor for human respiration monitoring. Humidity sensing behavior of the polymerbased planar devices, in which a polyethylene oxide-phosphotungstic acid (PEO-PWA) thin film is placed between an opposing inert electrodes, have been investigated by optimizing the device configuration and PWA salt concentration in the PEO matrix. The ultrafast response (~50 ms) and recovery (~52 ms) of the humidity sensor enabled us to study the real-time human respiration monitoring. Using morphological analysis, it is proposed that the ultrafast response-recovery time for this sensor is ascribed to their self-assembled lamellar-like structures of the PEO-PWA matrix polymer, which provides long-range continuous proton transport path in the polymer interface.

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

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.

Self-Assembled Photonic Microsensors with Strong Aggregation-Induced Emission for Ultra-Trace Quantitative Detection

ACS Nano ◽  
2021 ◽  
Vol 15 (3) ◽  
pp. 5534-5544
Author(s):  
Qiu-Jun Liu ◽  
Yulian Li ◽  
Jing-Cheng Xu ◽  
Hai-Feng Lu ◽  
Yuesheng Li ◽  
...  
Keyword(s):  
Quantitative Detection ◽  
Aggregation Induced Emission ◽  
Self Assembled ◽  
Ultra Trace

scholarly journals Highly sensitive detection of nitrobenzene by a series of fluorescent 2D zinc(ii) metal–organic frameworks with a flexible triangular ligand

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 23975-23984
Author(s):  
Xue Yang ◽  
Yixia Ren ◽  
Hongmei Chai ◽  
Xiufang Hou ◽  
Zhixiang Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Organic Frameworks ◽  
High Sensitivity ◽  
Fluorescent Sensors ◽  
Sensitive Detection ◽  
Donor Ligands ◽  
Highly Sensitive ◽  
Metal Organic ◽  
Highly Sensitive Detection

Four fluorescent 2D Zn-MOFs based on a flexible triangular ligand and linear N-donor ligands are hydrothermally prepared and used to detect nitrobenzene in aqueous solution with high sensitivity, demonstrating their potential as fluorescent sensors.

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