scholarly journals Printable elastomeric electrodes with sweat-enhanced conductivity for wearables

2021 ◽  
Vol 7 (29) ◽  
pp. eabg8433
Author(s):  
Jian Lv ◽  
Gurunathan Thangavel ◽  
Yi Li ◽  
Jiaqing Xiong ◽  
Dace Gao ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Wearable Devices ◽  
Urethane Acrylate ◽  
Wearable Electronics ◽  
Partial Removal ◽  
Current Collectors ◽  
Human Sweat ◽  
Silver Flakes ◽  
Enhanced Conductivity ◽  
Insight Into

We rationally synthesized the thermoplastic and hydrophilic poly(urethane-acrylate) (HPUA) binder for a type of printable and stretchable Ag flakes–HPUA (Ag-HPUA) electrodes in which the conductivity can be enhanced by human sweat. In the presence of human sweat, the synergistic effect of Cl− and lactic acid enables the partial removal of insulating surfactant on silver flakes and facilitates sintering of the exposed silver flakes, thus the resistance of Ag-HPUA electrodes can be notably reduced in both relaxed and stretched state. The on-body data show that the resistance of one electrode has been decreased from 3.02 to 0.62 ohm during the subject’s 27-min sweating activity. A stretchable textile sweat-activated battery using Ag-HPUA electrodes as current collectors and human sweat as the electrolyte was constructed for wearable electronics. The enhanced conductivity of the wearable wiring electrode from the reaction with sweat would provide meritorious insight into the design of wearable devices.

scholarly journals Breathable Materials for Triboelectric Effect-Based Wearable Electronics

2018 ◽  
Vol 8 (12) ◽  
pp. 2485 ◽  
Author(s):  
Congju Li ◽  
Ran Cao ◽  
Xiuling Zhang
Keyword(s):  
Recent Progress ◽  
Dielectric Materials ◽  
Wearable Devices ◽  
Wearable Electronics ◽  
Practical Application ◽  
Metal Mesh ◽  
Frictional Materials ◽  
Nanofiber Membranes ◽  
Materials Used ◽  
Triboelectric Effect

Wearable electronics are believed to be the future of the next-generation electric devices. However, the comfort of current wearable devices is greatly limited due to the use of airtight materials, which may even lead to inflammation of the skin. Therefore, breathable, skin-friendly materials, are highly desired for wearable devices. Here, the recent progress of the breathable materials used to fabricate skin-friendly electronics is reviewed by taking triboelectric effect-based wearable electronics as a typical example. Fibers, yarns, textiles, and nanofiber membranes are the most popular dielectric materials that serve as frictional materials. Metal mesh, silver yarn, and conductive networks made up of nanomaterial are preferred as air-permissive electrodes. The breathable materials for skin-friendly wearable electronics summarized in this review provide valuable references for future fabrication of humanized wearable devices and hold great significance for the practical application of wearable devices.

scholarly journals The environmental navigation using geometric virtual reality

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878363 ◽  
Author(s):  
Nien-Tsu Hu ◽  
Pu-Sheng Tsai ◽  
Ter-Feng Wu ◽  
Jen-Yang Chen ◽  
Lin Lee
Keyword(s):  
Virtual Reality ◽  
System Architecture ◽  
Three Dimensional ◽  
Wearable Devices ◽  
Wireless Transmission ◽  
Wearable Electronics ◽  
Virtual Reality Environment ◽  
Landscape Models ◽  
Three Dimensional Models ◽  
Animation Software

This article explores the construction of a geometric virtual reality platform for the environmental navigation. Non-panoramic photos and wearable electronics with Bluetooth wireless transmission functions are used to combine the user’s actions with the virtual reality environment in a first-person virtual reality platform. The 3ds Max animation software is used to create three-dimensional models of real buildings. These models are combined with the landscape models in Unity3d to create a virtual campus scene that matches real landscape. The wearable device included an ATMega168 chip as a microcontroller; it was connected to a three-axis accelerometer, a gyroscope, and a Bluetooth transmitter to detect and transmit various movements of the user. Although the development of the mechatronics, software, and engineering involved in the three-dimensional animation are the main objective, we believe that the methods and techniques can be modified for various purposes. After the system architecture was created and the operations of the platform were verified, wearable devices and virtual reality scenes are concluded to be able to be used together seamlessly.

scholarly journals Human Machine and Thermoelectric Energy Scavenging for Wearable Devices

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Vladimir Leonov
Keyword(s):  
Thermal Properties ◽  
Heat Flow ◽  
Thermal Resistance ◽  
Wearable Devices ◽  
The Body ◽  
Energy Scavenging ◽  
Wearable Electronics ◽  
Ambient Temperatures ◽  
Thermoelectric Energy ◽  
Temperature Heat

Thermal properties of humans were studied in the case where a small-size energy scavenger is placed on the body. In such a case, the human being serves as a heat source for the thermopile of the scavenger, but the latter serves as a thermally insulating object. As a result, the body properties, namely, the skin temperature, heat flow, and thermal resistance locally change. This is the result of redirection of heat flow inside the body to colder zones because of thermal insulation provided by the scavenger. Increased thermal resistance of human body, in turn, affects the design of the scavenger. The analysis of such scavenger performed for ambient temperatures of 0°C to 25°C shows that it could reach competitive performance characteristics and replace batteries in low-power wearable electronics. A simulated power of up to 60 μW/cm2 at 0°C has been validated by using wearable thermoelectric modules.

ChemInform Abstract: Synthesis of T-Shaped Oxazolonaphthoimidazo[1,2-a]pyridines Using Lactic Acid as Bio-Based Green Solvent: An Insight into Photophysical Studies.

ChemInform ◽  
2016 ◽  
Vol 47 (48) ◽  
Author(s):  
Umamahesh Balijapalli ◽  
Manojkumar Dhanthalu Thiyagarajan ◽  
Saravanakumar Manickam ◽  
Kulathu Iyer Sathiyanarayanan
Keyword(s):  
Lactic Acid ◽  
Green Solvent ◽  
Photophysical Studies ◽  
Insight Into

Aggregation of lactic acid in cold rare-gas matrices and the link to solution: a matrix isolation-vibrational circular dichroism study

2019 ◽  
Vol 21 (7) ◽  
pp. 3574-3584 ◽  
Author(s):  
Angelo Shehan Perera ◽  
Joseph Cheramy ◽  
Mohammad Reza Poopari ◽  
Yunjie Xu
Keyword(s):  
Lactic Acid ◽  
Circular Dichroism ◽  
Matrix Isolation ◽  
Vibrational Circular Dichroism ◽  
Rare Gas ◽  
Spectral Features ◽  
Circular Dichroïsm ◽  
Self Aggregation ◽  
Insight Into

Crucial insight into lactic acid self-aggregation in solution is obtained by following its unique VCD spectral features in cold matrices.

scholarly journals Li-ion battery material under high pressure: amorphization and enhanced conductivity of Li4Ti5O12

2018 ◽  
Vol 6 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Yanwei Huang ◽  
Yu He ◽  
Howard Sheng ◽  
Xia Lu ◽  
Haini Dong ◽  
...  
Keyword(s):  
High Pressure ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Ion Migration ◽  
Order Of Magnitude ◽  
Li Ion ◽  
Battery Material ◽  
Enhanced Conductivity ◽  
Insight Into

Abstract Lithium titanium oxide (Li4Ti5O12, LTO), a ‘zero-strain’ anode material for lithium-ion batteries, exhibits excellent cycling performance. However, its poor conductivity highly limits its applications. Here, the structural stability and conductivity of LTO were studied using in situ high-pressure measurements and first-principles calculations. LTO underwent a pressure-induced amorphization (PIA) at 26.9 GPa. The impedance spectroscopy revealed that the conductivity of LTO improved significantly after amorphization and that the conductivity of decompressed amorphous LTO increased by an order of magnitude compared with its starting phase. Furthermore, our calculations demonstrated that the different compressibility of the LiO6 and TiO6 octahedra in the structure was crucial for the PIA. The amorphous phase promotes Li+ diffusion and enhances its ionic conductivity by providing defects for ion migration. Our results not only provide an insight into the pressure depended structural properties of a spinel-like material, but also facilitate exploration of the interplay between PIA and conductivity.

Synthesis of T-shaped Oxazolonaphthoimidazo[1,2-a]pyridines using Lactic Acid as Bio-based Green Solvent: An Insight into Photophysical Studies

2016 ◽  
Vol 1 (11) ◽  
pp. 2900-2908 ◽  
Author(s):  
Umamahesh Balijapalli ◽  
Manojkumar Dhanthalu Thiyagarajan ◽  
Saravanakumar Manickam ◽  
Kulathu Iyer Sathiyanarayanan
Keyword(s):  
Lactic Acid ◽  
Green Solvent ◽  
Photophysical Studies ◽  
Insight Into
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