Highly flexible, high-performance radio-frequency antenna based on free-standing graphene/polymer nanocomposite film

2022 ◽  
pp. 152455
Author(s):  
Hoyun Jeon ◽  
Sehoon Jin ◽  
Keun-Young Shin
2010 ◽  
Vol 123-125 ◽  
pp. 109-112 ◽  
Author(s):  
Song Min Shang ◽  
Wei Zeng ◽  
Xiao Ming Tao

In recent decades, stretchable conductive polymers have gained extensive interest of researchers because of their hi-tech applications in electronics, textiles and medicine devices. In this study, carbon nanotubes and carbon nanospheres, as the chemically stable dopants, were uniformly dispersed in a polyurethane matrix to develop a highly elastic and stretchable conductive polymer composite film. The nanocomposite film inherited the advantageous properties from its constituents, namely the high conductivity from carbon nanotubes and nanospheres, and the elastomeric mechanical properties from the polyurethane. The conductive polymer nanocomposite film can be uniaxially and biaxially stretched up to 50% without clearly mechanical or electrical changes. Stretching beyond 50% would result in the conductivity decreasing gradually. Therefore, the as-prepared stretchable conductive polymer nanocomposites possessed both the high conductivity and the high elasticity, which would have greater application potential in high-performance electronic circuits.


2021 ◽  
Vol 17 (7) ◽  
pp. 155014772110248
Author(s):  
Miaoyu Li ◽  
Zhuohan Jiang ◽  
Yutong Liu ◽  
Shuheng Chen ◽  
Marcin Wozniak ◽  
...  

Physical health diseases caused by wrong sitting postures are becoming increasingly serious and widespread, especially for sedentary students and workers. Existing video-based approaches and sensor-based approaches can achieve high accuracy, while they have limitations like breaching privacy and relying on specific sensor devices. In this work, we propose Sitsen, a non-contact wireless-based sitting posture recognition system, just using radio frequency signals alone, which neither compromises the privacy nor requires using various specific sensors. We demonstrate that Sitsen can successfully recognize five habitual sitting postures with just one lightweight and low-cost radio frequency identification tag. The intuition is that different postures induce different phase variations. Due to the received phase readings are corrupted by the environmental noise and hardware imperfection, we employ series of signal processing schemes to obtain clean phase readings. Using the sliding window approach to extract effective features of the measured phase sequences and employing an appropriate machine learning algorithm, Sitsen can achieve robust and high performance. Extensive experiments are conducted in an office with 10 volunteers. The result shows that our system can recognize different sitting postures with an average accuracy of 97.02%.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2942
Author(s):  
Bhausaheb V. Tawade ◽  
Ikeoluwa E. Apata ◽  
Nihar Pradhan ◽  
Alamgir Karim ◽  
Dharmaraj Raghavan

The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the ”grafting from” and ”grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.


Nanoscale ◽  
2021 ◽  
Author(s):  
Chenxi Gao ◽  
Jiawei Wang ◽  
Yuan Huang ◽  
Zixuan Li ◽  
Jiyan Zhang ◽  
...  

Zinc-ion batteries (ZIBs) have attracted significant attention owing to their high safety, high energy density, and low cost. ZIBs have been studied as a potential energy device for portable and...


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