Nanowerk April 18, 2022 Until now, studies on wireless energy transfer (WET) have been mainly based on the electromagnetic (EM) induction method using EM waves. However, it is still challenging to utilize current EM wave mediated WET in those areas where it is most needed: underwater, body-implant, and EM-shielded cases (liquid/metals). Researchers in South Korea have developed a triboelectric acoustic energy transfer (AET) module by tuning the work function of the triboelectric layer via the large polarization of the embedded relaxor single crystal. The uniform displacement, a quasi-mode oscillation, across the flexible electrode surface in response to the square wave […]
Tag Archives: S&T South Korea
Development of stretchable and printable free-form lithium-ion batteries
Nanowerk March 25, 2022 Researchers in South Korea have developed a fully stretchable lithium-ion battery system using stretchable electrode. It acquires intrinsic stretchability and improved interfacial adhesion with the active materials via a functionalized physically cross-linked organogel as a stretchable binder and separator. The stretchable current collectors are fabricated in the form of nanocomposites consisting of a matrix with excellent barrier properties without swelling in organic electrolytes and nanostructure-controlled multimodal conductive fillers. They demonstrated several types of stretchable lithium-ion batteries that reliably operated under various stretch deformations with capacity and rate capability comparable with a nonstretchable batteries even under high […]
Photonic encryption platform in the ultraviolet and visible
Science Daily March 17, 2022 Researchers in South Korea have developed an optical encryption platform that works simultaneously in the visible and ultraviolet (UV) regimes. They adjusted the physical properties of silicon nitride to reduce its tendency to absorb ultraviolet light. They fabricated a metahologram in which an image clearly appears when ultraviolet laser is irradiated on it. They combined the two metaholograms that work in the ultraviolet and visible light regions to create an anticounterfeiting device that displays a unique product number. The hologram that appears when a visible light laser is irradiated acts as a key and when […]
‘Fingerprint’ machine learning technique identifies different bacteria in seconds
Phys.org March 4, 2022 Researchers in South Korea have demonstrated a markedly simpler, faster, and effective route to classify signals of two common bacteria E. coli and S. epidermidis and their resident media without any separation procedures by using surface-enhanced Raman spectroscopy (SERS) analysis boosted with a newly proposed deep learning model named dual-branch wide-kernel network (DualWKNet). With outstanding classification accuracies up to 98%, the synergistic combination of SERS and deep learning serves as an effective platform for “separation-free“ detection of bacteria in arbitrary media with short data acquisition times and small amounts of training data. Universal and fast bacterial […]
Study raises new possibilities for triggering room-temperature superconductivity with light
Phys.org March 9, 2022 In the case of the superconducting material yttrium barium copper oxide, or YBCO, experiments have shown that under certain conditions, knocking it out of equilibrium with a laser pulse allows it to superconduct at much closer to room temperature than researchers expected. YBCO switches from a normal to a superconducting state when chilled below a certain transition temperature or it can be switched off with a pulse of light. An international team of researchers (South Korea, USA – SLAC National Accelerator Laboratory, Japan, Germany) compared the two switching approaches (exposing to high magnetic field and laser […]
Power at sea: Towards high-performance seawater batteries
Science Daily January 31, 2022 Despite the many potential applications of seawater batteries (SWBs), the limited performance of available materials has hindered their commercialization. Researchers in South Korea have developed a process called ‘plasma in liquid,’ which involves preparing a mixture of precursors containing carbon, N, and S and discharging plasma into the solution resulting in a material with high doping levels of N and S with a structural backbone of carbon black. Experimentally they have confirmed that the material showed great potential for SWBs. The co-doped anode material exhibited remarkable electrochemical performance in SWBs, with a cycling life of […]
Suiting up with Al-Mg-Si: New protective coating for steel in ships and marine and coastal facilities
Phys.org January 5, 2022 Improving the corrosion resistance of steel by coating it with aluminum for marine applications is limited because of chloride ions in sea water on aluminum. Researchers in South Korea fabricated alloy films with excellent corrosion resistance by depositing an Mg film on Al-Si coated steel sheets and applying heat treatment. The fabricated Al-Mg-Si alloy film formed a corrosion product film composed of two layers, showing an excellent barrier effect against corrosion factors. The Mg in the film fabricated by heat treatment for 5 min was widely distributed in a dissolved state on the AI phase and […]
Flexible, stretchable battery capable of moving smoothly like snake scales
Nanowerk September 28, 2021 Researchers in South Korea have made a structure with individual, overlapping units, similar to snake scales that can be used to construct shape-morphing batteries for untethered soft robots. They created it by folding well-defined, two-dimensional patterns with cutouts, the folding lines mimicking the hinge structure of snakeskin, enabling stable deformations without mechanical damage to rigid cells. The structure is applied to a stretchable Li-ion battery, constructed to form an arrangement of electrically interconnected, hexagonal pouch cells. Simulation confirmed that the battery maintains its performance under dynamic deformation with a 90% stretching ratio and 10-mm-radius bending curve, […]
New DNA-based chip can be programmed to solve complex math problems
Science Daily September 14, 2021 The reactions in DNA-based combinational logic computing are mostly achieved through a manual process. For DNA-based Boolean logic, researchers in South Korea have fabricated a DNA-based microfluidic processing unit (MPU). They cast polydimethylsiloxane using double-sided molding techniques for alignment between the microfluidics and valve switch. For a uniform surface, molds fabricated using a three-dimensional printer were spin-coated by a polymer. For programming control, the valve switch arms were operated by servo motors. In the MPU controlled via a personal computer or smartphone application, the molecules with two input DNAs and a logic template DNA were […]
Quantum emitters: Beyond crystal clear to single-photon pure
Phys.org September 2, 2021 Quantum dots often suffer from adjacent unwanted emitters, which contribute to the background noise of the QD emission and fundamentally limit the single-photon purity. Researchers in South Korea developed a technique that can isolate the desired quality emitter by reducing the noise surrounding the target with what they have dubbed a ‘nanoscale focus pinspot. The technique is a structurally nondestructive technique under an extremely low dose ion beam and is generally applicable for various platforms to improve their single-photon purity while retaining the integrated photonic structures. Using this technique they focused the ion beam on a […]