A flexible humidity sensor based on silk fabrics for human respiration monitoring

2018 ◽  
Vol 6 (16) ◽  
pp. 4549-4554 ◽  
Author(s):  
Bintian Li ◽  
Gang Xiao ◽  
Feng Liu ◽  
Yan Qiao ◽  
Chang Ming Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electroless Plating ◽  
Humidity Sensor ◽  
Spray Coating ◽  
Silk Fabric ◽  
Respiration Monitoring ◽  
Interdigital Electrodes ◽  
Human Respiration ◽  
Respiration Sensor ◽  
Silk Fabrics

In this study, a silk fabric-based human respiration sensor was fabricated by successive electroless plating of conductive interdigital electrodes and spray-coating of a graphene oxide sensing layer.

High-Sensitivity Wearable and Flexible Humidity Sensor Based on Graphene Oxide/Non-Woven Fabric for Respiration Monitoring

Langmuir ◽  
2020 ◽  
Vol 36 (32) ◽  
pp. 9443-9448 ◽  
Author(s):  
Yamei Wang ◽  
Liwen Zhang ◽  
Zhenwei Zhang ◽  
Pengyuan Sun ◽  
Huawei Chen
Keyword(s):  
Graphene Oxide ◽  
Humidity Sensor ◽  
High Sensitivity ◽  
Woven Fabric ◽  
Respiration Monitoring

Cu(OH)2 nanowires/graphene oxide composites based QCM humidity sensor with fast-response for real-time respiration monitoring

2020 ◽  
Vol 304 ◽  
pp. 127313 ◽  
Author(s):  
Han Fang ◽  
Jianbin Lin ◽  
Zhixiang Hu ◽  
Huan Liu ◽  
Zirong Tang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Real Time ◽  
Humidity Sensor ◽  
Fast Response ◽  
Respiration Monitoring ◽  
Oxide Composites

scholarly journals An ultrafast-response and flexible humidity sensor for human respiration monitoring and noncontact safety warning

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaoyi Wang ◽  
Yang Deng ◽  
Xingru Chen ◽  
Peng Jiang ◽  
Yik Kin Cheung ◽  
...  
Keyword(s):  
Double Layer ◽  
Humidity Sensor ◽  
Flexible Substrate ◽  
Ammonium Ion ◽  
Electrical Safety ◽  
Humidity Sensors ◽  
Parylene C ◽  
Respiration Monitoring ◽  
Safety Warning ◽  
Human Respiration

AbstractThe humidity sensor is an essential sensing node in medical diagnosis and industrial processing control. To date, most of the reported relative humidity sensors have a long response time of several seconds or even hundreds of seconds, which would limit their real application for certain critical areas with fast-varying signals. In this paper, we propose a flexible and low-cost humidity sensor using vertically aligned carbon nanotubes (VACNTs) as electrodes, a PDMS-Parylene C double layer as the flexible substrate, and graphene oxide as the sensing material. The humidity sensor has an ultrafast response of ~20 ms, which is more than two orders faster than most of the previously reported flexible humidity sensors. Moreover, the sensor has a high sensitivity (16.7 pF/% RH), low hysteresis (<0.44%), high repeatability (2.7%), good long-term stability, and outstanding flexibility. Benefiting from these advantages, especially the fast response, the device has been demonstrated in precise human respiration monitoring (fast breathing, normal breathing, deep breathing, asthma, choking, and apnea), noncontact electrical safety warning for bare hand and wet gloves, and noncontact pipe leakage detection. In addition, the facile fabrication of the flexible platform with the PDMS-Parylene C double layer can be easily integrated with multisensing functions such as pH sensing, ammonium ion sensing, and temperature sensing, all of which are useful for more pattern recognition of human activity.

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.

Graphene oxide modified carbon fiber reinforced epoxy composites

2020 ◽  
Vol 40 (5) ◽  
pp. 415-420 ◽  
Author(s):  
Yasin Altin ◽  
Hazal Yilmaz ◽  
Omer Faruk Unsal ◽  
Ayse Celik Bedeloglu
Keyword(s):  
Graphene Oxide ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Spray Coating ◽  
Sem Analysis ◽  
Epoxy Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Quick Method ◽  
Carbon Fiber Reinforced

AbstractThe interfacial interaction between the fiber and matrix is the most important factor which influences the performance of the carbon fiber-epoxy composites. In this study, the graphitic surface of the carbon fibers was modified with graphene oxide nanomaterials by using a spray coating technique which is an easy, cheap, and quick method. The carbon fiber-reinforced epoxy matrix composites were prepared by hand layup technique using neat carbon fibers and 0.5, 1 and 2% by weight graphene oxide (GO) modified carbon fibers. As a result of SEM analysis, it was observed that GO particles were homogeneously coated on the surface of the carbon fibers. Furthermore, Young's modulus increased from 35.14 to 43.40 GPa, tensile strength increased from 436 to 672 MPa, and the elongation at break was maintained around 2% even in only 2% GO addition.

The optimized SAW humidity sensor with nanofilms of graphene oxide

2013 ◽  
Author(s):  
S. M. Balashov ◽  
O. V. Balachova ◽  
A. V. U. Braga ◽  
M. C. Q. Bazetto ◽  
A. Pavani Filho
Keyword(s):  
Graphene Oxide ◽  
Humidity Sensor

Dyeing of Silk Fabric with Extracted Dyes from Lichens

2015 ◽  
Vol 1134 ◽  
pp. 165-170
Author(s):  
Nor Atiqah Mohamed ◽  
Mohd Rozi Ahmad ◽  
Muhammad Ismail Abd Kadir ◽  
Asmida Ismail ◽  
Wan Yunus Wan Ahmad
Keyword(s):  
Boiling Water ◽  
Silk Fabric ◽  
Fastness Properties ◽  
Natural Dyeing ◽  
Fermentation Method ◽  
Silk Fabrics ◽  
Colour Coordinates

Two lichens species (ParmotremapraesorediosumandHeterodermialeucomelos)were assessed for dye production using boiling water method (BWM) and ammonia fermentation method (AFM). The dyes were applied on silk fabric. Three types of mordant were used i.e. alum, iron and vinegar through meta-chrome (simultaneous) method of natural dyeing. The K/S values, colour coordinates values and colour differences (ΔE) of the dyed samples were measured. Dyeing fastness properties of the dyed silk fabrics were assessed for washing, rubbing and light. TheP.praesorediosumextracts yielded beige to dull brown shades using BWM and pinkish-purple using AFM, whereas theH.leucomelosextracts produced yellowish-brown shades for both BWM and AFM on the silk substrate. Modanting seemed to be effective in increasing the K/S values of all mordanted fabrics except in the case of silk fabric dyed withP.praesorediosumextracted from AFM. Fastness ratings to washing and rubbing were all very good (5-4) for bothP.praesorediosumandH.leucomelosdyed silk fabrics. The fabrics dyed withP.praesorediosumandH.leucomelosextracts produced strong and deep colours as their ΔE values were higher and increased obviously of all mordanted fabrics. It can be concluded thatP.praesorediosumandH.leucomelosextracted from BWM and AFM methods can be used as an alternative dye source.

scholarly journals Fabrication Techniques for Graphene Oxide-Based Molecular Separation Membranes: Towards Industrial Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 757
Author(s):  
Ohchan Kwon ◽  
Yunkyu Choi ◽  
Eunji Choi ◽  
Minsu Kim ◽  
Yun Chul Woo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Large Scale ◽  
Spray Coating ◽  
Dip Coating ◽  
Small Scale ◽  
Scale Production ◽  
Separation Membranes ◽  
Current Review ◽  
Slot Die ◽  
Continuous Fabrication

Graphene oxide (GO) has been a prized material for fabricating separation membranes due to its immense potential and unique chemistry. Despite the academic focus on GO, the adoption of GO membranes in industry remains elusive. One of the challenges at hand for commercializing GO membranes lies with large-scale production techniques. Fortunately, emerging studies have acknowledged this issue, where many have aimed to deliver insights into scalable approaches showing potential to be employed in the commercial domain. The current review highlights eight physical methods for GO membrane fabrication. Based on batch-unit or continuous fabrication, we have further classified the techniques into five small-scale (vacuum filtration, pressure-assisted filtration, spin coating, dip coating, drop-casting) and three large-scale (spray coating, bar/doctor blade coating, slot die coating) approaches. The continuous nature of the large-scale approach implies that the GO membranes prepared by this method are less restricted by the equipment’s dimensions but rather the availability of the material, whereas membranes yielded by small-scale methods are predominately limited by the size of the fabrication device. The current review aims to serve as an initial reference to provide a technical overview of preparing GO membranes. We further aim to shift the focus of the audience towards scalable processes and their prospect, which will facilitate the commercialization of GO membranes.

Tuning the cationic ratio of Fe1CoxNiyP integrated on Vertically aligned reduced graphene oxide array via electroless plating as efficient self-supported bifunctional electrocatalyst for water splitting

2021 ◽  
pp. 1-33
Author(s):  
Kaiming Guo ◽  
Firdoz Shaik ◽  
Jine Yang ◽  
Bin Jiang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Water Splitting ◽  
Electroless Plating ◽  
Cost Effective ◽  
Bifunctional Electrocatalyst ◽  
Reduced Graphene ◽  
Wide Ph Range ◽  
Vertically Aligned ◽  
Ph Range

Abstract Water splitting is considered as a potential sustainable and green technology for producing mass hydrogen and oxygen. A cost-effective self-supported stable electrocatalyst with excellent electrocatalytic performance in a wide pH range is greatly required for water splitting. This work reports on the synthesis and anchoring of Fe1CoxNiyP nanoparticles on vertically aligned reduced graphene oxide array (VrGO) via electroless plating. The catalytic activity of Fe1CoxNiyP nanoparticles is tuned finely by tailoring the cationic ratio of Co and Ni. Fe1Co2Ni1P/VrGO exhibits the lowest overpotential (58 and 110 mV) at 10 mA cm−2 and lowest tafel slope (31 and 33 mV dec−1) for hydrogen evolution reaction in 1.0 M KOH and 0.5 M H2SO4 respectively. Fe1Co1Ni2P/VrGO exhibits the lowest overpotential (173 mV) at 10 mA cm−2 with lowest tafel slope (47 mV dec-1) for oxygen evolution reaction. The enhanced performance of the electrocatalyst is attributed to improved electrical conductivity, synergistic effects and beneficial electronic states caused by the appropriate atomic ratio of Co and Ni in the bifunctional electrocatalyst. This study helps to explore the effect of variable cationic ratio in the cost-effective ternary iron group metal phosphides electrocatalysts to achieve enhanced electrocatalytic performance for water splitting in a wide pH range.

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