Phys.org December 9, 2024 Gel-based sensors typically depend on a metal grid connection, which is susceptible to structural deformation under heavy stress applications and necessitates external power. Researchers in South Korea developed gel polymer electrode-based triboelectric nanogenerator (GPE-TENG) that was stretchable, semi-transparent, and durable, designed to enable a self-powered touch panel for intelligent touch perception. The ionic polymer gel encapsulated within the ecoflex ensured robust adhesion of the ionic conductive polymer gel (PEO/LiTFSI) to the ecoflex layers. It demonstrated high durability, enduring stretching of approximately 375 % and sustaining heavy mechanical deformations over a long period without loss of functionality. […]
Tag Archives: S&T South Korea
Self-heating flexible electronics lower manufacturing temperature requirements
Nanowerk December 2, 2024 Researchers in South Korea developed high-performance flexible oxide thin-film transistors (TFTs) using SnO2 semiconductor and high-k ZrO2 dielectric, both formed through combustion-assisted sol-gel processes. The method involved the exothermic reaction of fuels and oxidizers to produce high-quality oxide films without extensive external heating. The combustion ZrO2 films had an amorphous structure, a higher proportion of oxygen corresponding to the oxide network, which contributed to the low leakage current and frequency-independent dielectric properties. The zirconium dioxide TFTs fabricated on flexible substrates exhibited excellent electrical characteristics, field-effect mobility, subthreshold swing, and an on/off current ratio of 1.13 × 106 at […]
Researchers develop technology to mass produce quantum dot lasers for optical communications
Phys.org June 28, 2024 To produce 75 °C continuous-wave operation research in South Korea investigated InAs/GaAs quantum dot laser diodes (QDLDs) on a GaAs substrate grown by utilizing all-metalorganic chemical vapor deposition technology with a p-AlGaAs cladding layer. The InAs quantum dots (QDs) in a dot-in-a-well (DWELL) structure formed by engineering the strained bottom InGaAs layer were successfully grown without detectable clusters, making it possible to increase the number of DWELL stacks effectively. The results of electron-channeling contrast imaging revealed that dislocations in the p-cladding layer were generated due to the accumulative strain of the DWELL and low-temperature growth. The […]
Scientists develop the next generation of highly efficient memory materials with atom-level control
Phys.org June 27, 2024 Recently a single-phase material concurrently exhibiting magnetism and the spin Hall effect has emerged as a scientifically and technologically interesting platform for realizing efficient and compact spin–orbit torque (SOT) systems. Researchers in South Korea demonstrated external-magnetic-field-free switching of perpendicular magnetization in a single-phase ferromagnetic and spin Hall oxide SrRuO3 by delicately altering the local lattices of the top and bottom surface layers of SrRuO3, while retaining a quasi-homogeneous, single-crystalline nature of the SrRuO3 bulk. This led to unbalanced spin Hall effects between the top and bottom layers. SrRuO3 exhibited the highest SOT efficiency and lowest power […]
Innovative bird-eye-inspired camera developed for enhanced object detection
Science Daily May 30, 2024 Despite notable advances in artificial vision systems that mimic animal vision, the exceptional object detection and targeting capabilities of avian eyes via foveated and multispectral imaging remain underexplored. Researchers in South Korea have developed an artificial vision system that capitalizes on these aspects of avian vision by vertically stacking perovskite photodetector arrays whose designs were optimized by theoretical simulations for the demonstration of foveated and multispectral imaging. The artificial vision system successfully identified colored and mixed-color objects and detected remote objects through foveated imaging. They discussed the potential for its use in uncrewed aerial vehicles […]
Charge your laptop in a minute? Supercapacitors can help; new research offers clues
Phys.org May 25, 2024 The current understanding of electric double layer (EDL) charging is limited to simple geometries. An international team of researchers (USA – University of Colorado, Poland) introduced a model to predict electrolyte transport in complex networks of slender pores. Their methodology accurately captures the spatial and temporal dependencies of charge density and electric potential, matching results obtained from computationally intensive direct numerical simulations. Their network model provided results up to six orders of magnitude faster. They used the framework to study the impact of pore connectivity and polydispersity on electrode charging dynamics for pore networks and discussed […]
Omnidirectional color wavelength tuning method unlocks new possibilities for smart photonics
Phys.org May 22, 2024 Ideally, on-demand omnidirectional wavelength control is highly desirable from the perspective of wavelength-tuning freedom. However, despite numerous previous research efforts on tunable chiral liquid crystals (CLCs) structural colors, only mono-directional wavelength tuning toward shorter wavelengths has been employed in most studies to date. Researchers in South Korea demonstrated the ideally desired omnidirectional wavelength control toward longer and shorter wavelengths with significantly improved tunability over a broadband wavelength range. They achieved simultaneous and omnidirectional structural color-tuning control by using areal expanding and contractive strain control of dielectric elastomer actuators (DEAs) with chiral liquid crystal elastomers (CLCEs). According […]
Metalens expands Its reach from light to sound
Science Daily May 14, 2024 An important hurdle for using metalenses for manipulating waves is due to the severe hampering of the angular response originating from coma and field curvature aberrations, which result in a loss of focusing ability. Researchers in South Korea developed a blueprint by introducing the notion of a wide field-of-hearing (FOH) metalens, designed particularly for capturing and focusing sound with decreased aberrations. Employing an aberration-free planar-thin metalens that leverages perfect acoustic symmetry conversion, they experimentally realized a robust wide FOH capability of approximately 140 deg. in angular range. The metalens featured a relatively short focal length, […]
Researchers develop nanotechnology for creating wafer-scale nanoparticle monolayers in seconds
Phys.org May 7, 2024 Underwater adhesion processes have faced challenges to uniformly transfer nanoparticles into a monolayer, particularly those below 100 nm in size, over large areas. Researchers in South Korea have developed a scalable “one-shot” self-limiting nanoparticle transfer technique, enabling the efficient transport of nanoparticles from water in microscopic volumes to an entire 2-inch wafer in a remarkably short time of 10 seconds to reach near-maximal surface coverage in a 2D mono-layered fashion. They used proton engineering in electrostatic assembly which accelerated the diffusion of nanoparticles resulting in a hundredfold faster coating speed than the previously reported results in […]
New metasurface innovation unlocks precision control in wireless signals
Nanowerk April 22, 2023 Polarization conversion and beam scanning metasurfaces are commonly used to reduce polarization mismatch and direct electromagnetic waves in a specific direction to improve the strength of a wireless signal. However, identifying suitable active and mechanically reconfigurable metasurfaces for polarization conversion and beam scanning is a considerable challenge, and the reported metasurfaces have narrow scanning ranges, are expensive, and cannot be independently controlled. Researchers in South Korea proposed a reconfigurable transmissive metasurface combined with a scissor and rotation actuator for independently controlling beam scanning and polarization conversion functions. They constructed metasurface with rotatable unit cells (UCs) that […]