scholarly journals Silver nanowire coated knitted wool fabrics for wearable electronic applications

2019 ◽  
Vol 14 ◽  
pp. 155892501985622 ◽  
Author(s):  
Alper Gurarslan ◽  
Büşra Özdemir ◽  
İbrahim Halil Bayat ◽  
Mustafa Berke Yelten ◽  
Güneş Karabulut Kurt

This study demonstrates a first example of silver nanowire coated wool fibers for wearable electronic applications. Silver nanowires were synthesized according to the polyol method and then drop casted on knitted wool fabrics. Electronic properties of the knitted samples were investigated under cyclic bending conditions. Conductive fabrics were isolated with a dielectric material and used as capacitance to measure respiration and finger motions. In addition, the same capacitor was employed as a pressure sensor and touch-based sensor for lighting up an LED. This study demonstrates that silver nanowire coated knitted wool fabrics can be used in electronic textiles not only as a flexible electrode but also as a capacitor for different applications.

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1088
Author(s):  
Stefan Schierle ◽  
Nils Straub ◽  
Peter Woias ◽  
Frank Goldschmidtboeing

An electrostatic membrane actuator with an elastomer membrane as movable part and silver nanowires (AgNWs) as flexible electrode material is built and characterized. A layered and modular actuator design facilitates simple and fast modification of actuator properties for characterization purposes. The tested actuators allow a membrane center deflection in the range of over 50 μm with applied voltages lower than 1 kV. The observable membrane center deflection exhibits a viscoelastic creep behavior. With the aim to achieve a more stable membrane deflection, a simple correction function was applied to the constant electrode voltage thus compensating the linear creep rate. With this method, the creep rate was changed from +0.27 μm/s to −0.08 μm/s. This method already improves the stability of the actuator deflection to a high degree.


Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Yue Li ◽  
Zhiguang Cao ◽  
Tie Li ◽  
Fuqin Sun ◽  
Yuanyuan Bai ◽  
...  

Biomimetic flexible tactile sensors endow prosthetics with the ability to manipulate objects, similar to human hands. However, it is still a great challenge to selectively respond to static and sliding friction forces, which is crucial tactile information relevant to the perception of weight and slippage during grasps. Here, inspired by the structure of fingerprints and the selective response of Ruffini endings to friction forces, we developed a biomimetic flexible capacitive sensor to selectively detect static and sliding friction forces. The sensor is designed as a novel plane-parallel capacitor, in which silver nanowire–3D polydimethylsiloxane (PDMS) electrodes are placed in a spiral configuration and set perpendicular to the substrate. Silver nanowires are uniformly distributed on the surfaces of 3D polydimethylsiloxane microcolumns, and silicon rubber (Ecoflex®) acts as the dielectric material. The capacitance of the sensor remains nearly constant under different applied normal forces but increases with the static friction force and decreases when sliding occurs. Furthermore, aiming at the slippage perception of neuroprosthetics, a custom-designed signal encoding circuit was designed to transform the capacitance signal into a bionic pulsed signal modulated by the applied sliding friction force. Test results demonstrate the great potential of the novel biomimetic flexible sensors with directional and dynamic sensitivity of haptic force for smart neuroprosthetics.


2018 ◽  
Vol 6 (47) ◽  
pp. 12940-12947 ◽  
Author(s):  
Jialin Liu ◽  
Tengyu He ◽  
Guangqiang Fang ◽  
Ranran Wang ◽  
Elbadawy A. Kamoun ◽  
...  

Two kinds of silk nanofibril/silver nanowire composite films were fabricated by using a facile vacuum-filtration method, and can act as a humidity sensor or a pressure sensor.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jean G. de Oliveira ◽  
Tausif Muhammad ◽  
Sohee Kim

Abstract Preterm infants are prone to have higher risks of morbidity, disability and developmental delay compared to term infants. The primitive reflexes, inborn behaviors found in early life development, are shown to be a good tool to assess the integrity of the central nervous system of infants and to predict potential malfunctions. Among these reflexes, the non-nutritive sucking reflex plays an important role in indicating congenital abnormalities in brain development and feeding readiness, especially for premature infants. Conventionally, pediatricians evaluate the oral sucking power qualitatively based on their experiences, by using a gloved finger put inside the infant’s mouth. Thus, more quantitative solutions to assess the sucking power of preterm infants are necessary to support healthcare professionals in their evaluation procedures. Here, we developed a silver nanowire (AgNW)-based flexible pressure sensor to measure the non-nutritive sucking power of infants. The flexible sensor was fabricated using silver nanowires deposited on polydimethylsiloxane (PDMS) in a sandwich-like structure. The sensor based on the principle of strain gauge was attached to a ring-shaped connecting module, and then to a pacifier. The negative sucking pressure exerted by the infant deformed the sensor membrane, causing its electrical resistance to change without any contact between the infant’s mouth and the sensing element. The fabricated sensor was characterized and optimized to achieve both the suitable sensitivity and stability. Thanks to the excellent long-term electro-mechanical stability and high sensitivity, the developed sensor is expected to provide the means to quantitatively assess the non-nutritive sucking of infants, with a portable, low-cost, non-invasive and light-weight solution.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
June Sik Hwang ◽  
Jong-Eun Park ◽  
Gun Woo Kim ◽  
Hyeono Nam ◽  
Sangseok Yu ◽  
...  

AbstractAs silver nanowires (Ag NWs) are usually manufactured by chemical synthesis, a patterning process is needed to use them as functional devices. Pulsed laser ablation is a promising Ag NW patterning process because it is a simple and inexpensive procedure. However, this process has a disadvantage in that target materials are wasted owing to the subtractive nature of the process involving the removal of unnecessary materials, and large quantities of raw materials are required. In this study, we report a minimum-waste laser patterning process utilizing silver nanoparticle (Ag NP) debris obtained through laser ablation of Ag NWs in liquid media. Since the generated Ag NPs can be used for several applications, wastage of Ag NWs, which is inevitable in conventional laser patterning processes, is dramatically reduced. In addition, electrophoretic deposition of the recycled Ag NPs onto non-ablated Ag NWs allows easy fabrication of junction-enhanced Ag NWs from the deposited Ag NPs. The unique advantage of this method lies in using recycled Ag NPs as building materials, eliminating the additional cost of junction welding Ag NWs. These fabricated Ag NW substrates could be utilized as transparent heaters and stretchable TCEs, thereby validating the effectiveness of the proposed process.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2219
Author(s):  
Xiaopeng Li ◽  
Jiayue Zhou ◽  
Dejun Yan ◽  
Yong Peng ◽  
Yong Wang ◽  
...  

In this paper, silver nanowires (AgNWs) with a diameter of 40 nm and a length of 45 μm were dispersed into an ethanol solution to prepare AgNW solutions with concentrations of 1, 2, and 3 mg/mL, respectively. The AgNW solutions were then deposited on a glass substrate using spin-coating at 1000, 2000, and 3000 rpm for 45 s, respectively, to prepare transparent electrodes. The results showed that the distribution of AgNWs on the substrate increased in density with the increase in the AgNW solution concentration and the decrease in spin speed. The effect of concentration on the distribution of AgNWs was greater than that of the spin speed. The transmittance of each electrode was between 84.19% and 88.12% at 550 nm, the average sheet resistance was between 20.09 and 358.11 Ω/sq, the highest figure of merit (FoM) was 104.42, and the lowest haze value was 1.48%. The electrode prepared at 1000 rpm with a concentration of 2 mg/mL and that prepared at 3000 rpm with a concentration of 3 mg/mL were very similar in terms of the average sheet resistance, transmittance at 550 nm, FoM, and haze value; thus, these two electrodes could be considered equivalent. The haze value of the electrode was positively correlated with the spin speed at low concentration, but that relationship became inverse as the concentration rose. For the AgNWs used in this experiment with an aspect ratio of 1125, the concentration of the AgNW solution should reach at least 2 mg/mL to ensure that the FoM of the electrode is greater than 35.


2011 ◽  
Vol 331 ◽  
pp. 377-381 ◽  
Author(s):  
Xue Mei He ◽  
Kong Liang Xie

In this study, wool fabrics were treated with different concentration of chitosan sulfamic acid solution under using 3-glycidyloxypropyltrimethoxysilane (GPTMS) as a crosslinking agent. The structure of treated wool fabrics was investigated by SEM, DSC-TG. Treated wool fibers had a irregular surface appearance, showed the presence of amounts of Nano SiO2 and their aggregates deposited onto surface of wool fibers. The thermal properties were obviously enhanced. Treated wool fabrics is more stable in higher temperature than that of untreatment. Treated wool fabrics were dyed with weak acid red B, and dyeing behaviour were studied by means of by light reflectance measurements. The color strength (K/S value) of treated wool fabrics obviousily increased from 5.33 to 31.68 by comparison with the untreatment. As a result, it can be concluded that the chitosan sulfamic acid solution with GPTMS treatment could improve the weak acid red B low temperature dyeing on wool. Further, low temperature dyeing of wool fabrics with chitosan-sulfamic acid is safe, so the results obtained are quite promising as a basis for possible future industrial application.


Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6390-6395 ◽  
Author(s):  
Ye Rim Lee ◽  
Hyungho Kwon ◽  
Do Hoon Lee ◽  
Byung Yang Lee

Electrodes consisting of silver nanowires and carbon nanotubes enable a dielectric elastomer actuator to become highly stretchable and optically transparent.


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