One of challenges existing in fiber‐based supercapacitors is how to achieve high energy density without compromising their rate stability. Owing to their unique physical, electronic, and ...electrochemical properties, two‐dimensional (2D) nanomaterials, e.g., molybdenum disulfide (MoS2) and graphene, have attracted increasing research interest and been utilized as electrode materials in energy‐related applications. Herein, by incorporating MoS2 and reduced graphene oxide (rGO) nanosheets into a well‐aligned multi‐walled carbon nanotube (MWCNT) sheet followed by twisting, MoS2‐rGO/MWCNT and rGO/MWCNT fibers are fabricated, which can be used as the anode and cathode, respectively, for solid‐state, flexible, asymmetric supercapacitors. This fiber‐based asymmetric supercapacitor can operate in a wide potential window of 1.4 V with high Coulombic efficiency, good rate and cycling stability, and improved energy density.
Starke Fasern: Ein unsymmetrischer fester Superkondensator mit Elektroden aus flexiblen Hybridfasern (Anode: MoS2‐rGO/MWCNT, Kathode: rGO/MWCNT; MWCNT: mehrwandige Kohlenstoffnanoröhre, rGO: reduziertes Graphenoxid) arbeitet stabil in einem weiten Potentialfenster von 1.4 V mit hohem Coulomb‐Wirkungsgrad und verbesserter Energiedichte.
Intelligent textiles provide an ideal platform for merging technology into daily routines. However, current textile electronic systems often rely on rigid silicon components, which limits seamless ...integration, energy efficiency, and comfort. Chipless electronic systems still face digital logic challenges owing to the lack of dynamic energy-switching carriers. We propose a chipless body-coupled energy interaction mechanism for ambient electromagnetic energy harvesting and wireless signal transmission through a single fiber. The fiber itself enables wireless visual-digital interactions without the need for extra chips or batteries on textiles. Because all of the electronic assemblies are merged in a miniature fiber, this facilitates scalable fabrication and compatibility with modern weaving techniques, thereby enabling versatile and intelligent clothing. We propose a strategy that may address the problems of silicon-based textile systems.
Weavable, high‐performance, solid‐state supercapacitors are prepared based on hybrid fibers made of sandwiched structure of multi‐walled carbon nanotube (MWCNT)/reduced graphene oxide (rGO)/MWCNT. ...Such supercapacitors exhibit excellent weavability, high volumetric capacitance and energy density, and good cycling stability owing to the high mechanical property and electrical conductivity of well‐aligned long MWCNTs, the incorporation of rGO nanosheets, and the unique sandwiched hybrid structure.
Clothing with electromagnetic functionalities can be used to interconnect a wireless network of battery-free sensors around the human body. Such smart clothing require textiles that are highly ...conductive, flexible, durable, and compatible with established manufacturing processes. Here, we demonstrate textiles with near-field functionalities fabricated by digital embroidery of liquid metal fibers. The liquid metal fibers, consisting of Galinstan in perfluoroalkoxy alkane tubing, exhibit mechanical flexibility comparable to the underlying materials and durability against mechanical bending (<1% electrical resistance variation on 10000 cycles), and high electrical conductance at radio-frequencies (~9.6 Ωm at 13.56 MHz). The digital embroidery process enables transfer of near-field inductive patterns optimized using full-wave electromagnetic simulations onto conventional textiles without blocking water vapour transport. We design and fabricate liquid metal fibers onto fabric skin patches for wireless power transfer at 13.56 MHz. Experiments show that the patches can conformally attach onto the surface of the body and provide robust wireless power transfer to devices in both wearable and implantable configurations during physical activity (<1.5% relative standard deviation during standing and running at 9.2 km/h), These results suggest the potential of liquid-metal based wireless systems to establish robust and unobtrusive wireless networks of battery-free wearable and implantable devices using near-field technologies.
Multiple sensors placed around the body can acquire important physiological data for applications in clinical diagnostics, athletics, and human-machine interfaces, but long-term powering of such a ...distributed network of sensors is a major technological challenge. Clothing embroidered with conductive inductor traces, termed near-field-enabled clothing, have recently been proposed for establishing network connectivity around the body by transferring power from a central hub (such as a smartphone) to multiple battery-free sensors. Here, we present a design procedure to optimize power transfer efficiency of such near-field-enabled clothing using both electromagnetic field simulation and equivalent circuit analysis. We describe the selection of appropriate parameters for optimization, and present an equivalent circuit model that provides design insights on the optimal parameters for wireless power transfer.
•A plasmonic perfect absorber (PA) was proposed to serve as a refractive index sensor.•The PA with a high quality-factor of 41.2 and an absorbance of 99.9% at 142.6THz.•Physics origin of PA is ...studied by field, current distribution and LC circuit model.•The PA for refractive index sensor yields a sensitivity of 1445nm/RIU.
We present a non-planar all-metal plasmonic perfect absorber (PA) with response polarization independent in infrared region, which can be served as a sensor for enhanced refractive index sensing. Distinct from previous designs, the proposed PA consisted of all metal structured film constructed with an assembly of four-tined rod resonators (FRRs). The PA with a high quality-factor (Q-factor) of 41.2 and an absorbance of 99.9% at 142.6THz has been demonstrated numerically. The resonance behavior occurs in the space between the rods of the FRRs, which is remarkable different conventional sandwiched structural PAs. Based on equivalent LC circuit theory, the absorption peak can be finely tuned by varying the geometrical dimensions of the FRRs. Furthermore, the resonance frequency shows highly sensitive response to the change of refractive index in the surrounding medium. A careful design for refractive index sensor can yield a sensitivity of 1445nm/refractive index unit (RIU) and a figure of merit (FOM) of 28.8. The demonstrated design of the plasmonic PA for sensing provides great potential application in enhancing refractive index sensors and the enhanced infrared spectroscopy.
In this paper, a tri-layer metamaterial composed of a split-disk structure array sandwiched with two layers of twisted sub-wavelength metal grating is proposed and investigated numerically in ...terahertz region. The numerical results exhibit that linear polarization conversion via diode-like asymmetric transmission for terahertz waves within ultra-broadband frequency range is achieved due to Fabry-Perot-like resonance. In our design, the conversion polarization transmission coefficient for normal incidence is greater than 90 % in the range of 0.23–1.17 THz, equivalent to 134.3 % relative bandwidth. The physical mechanism of the broadband linear polarization conversion effect is further illustrated by simulated electrical field distributions.
In this paper, a kind of bi-layered asymmetrical split ring metamaterial was proposed as a circular polarization converter. Simulations and experiments at the microwave regime showed that the ...proposed structures can achieve the conversions from right-handed circularly polarized electromagnetic waves to left-handed ones and the reversed conversions in the opposite propagating direction. The linear to circular polarization transmission coefficients and the surface currents were investigated to understand the mechanism of the circular polarization conversions. Moreover, we optimized the proposed metamaterials by increasing the distance between the two metal layers. The proposed circular polarization converters have applications in microwave wave plates and metamaterial antennas.
To promote the application of rubber-cement composites as the main bearing structure and key components in practical engineering under frequent dynamic disturbances, in this work, the split Hopkinson ...pressure bar (SHPB) cyclic impact tests of rubber-cement composite specimens with four different confine modes were carried out in which the impact load increased sequentially. The relationship between average strain rate, ultimate strain and impact times and the relationship between peak stress, damage energy, ultimate strain and incident energy were analyzed. The results showed that the appropriate confine reinforcement treatment can make rubber-cement composite give full play to its deformation ability when it was completely damaged. Carbon fiber-reinforced polymer (CFRP) sheet and steel cylinder can work together with the rubber-cement composite matrix to resist impact load, which effectively improves the structural strength, damage fracture energy, and cyclic impact resistance of the rubber-cement composite. Finally, based on the effect difference of confine modes, the simplified plane force models of rubber-cement composite specimens with four different confine modes were established, which clearly revealed the completely different impact resistance mechanism of the rubber-cement composites with different constraints under cyclic impact loading.
