Nanowerk February 28, 2023 Orbital angular momentum (OAM) is an important property of the electronic structure in materials that leads to magnetism. A team of researchers in the US (University of Kentucky, Argonne National Laboratory, Lawrence Livermore National Laboratory, Brookhaven National Laboratory, UC Berkeley) has developed and demonstrated a new technique that uses a special patterned array of engineered nanoscale magnets to impart OAM to X-ray beams. They examined an artificial spin crystal or spin “ice”, consisting of arrays of nanomagnets, and how it interacts with X-rays. OAM beams could be turned on and off by modest variations of temperature […]
Towards a new antenna paradigm with waveform-selective metasurfaces
Nanowerk February 28, 2023 Although various modulation schemes have been proposed to efficiently use the limited frequency resources by exploiting several degrees of freedom, antenna performance is essentially governed by frequency only. An international team of researchers (Japan, Italy, USA – UK) has proposed an antenna design concept based on metasurfaces to manipulate antenna performances in response to the time width of electromagnetic pulses. They numerically and experimentally showed that by using a proper set of spatially arranged metasurfaces loaded with lumped circuits, ordinary omnidirectional antennas could be reconfigured by the incident pulse width to exhibit directional characteristics varying over […]
Wafer-scale nanofabrication of telecom single-photon emitters in silicon
Phys.org February 23, 2023 Monolithic integration of single-photon sources in a controllable way would give a resource-efficient route to implement millions of photonic qubits in photon integrated circuits. To run quantum computation protocols, these photons must be indistinguishable. Building on their previous work researchers in Germany have shown how focused ion beams from liquid metal alloy ion sources are used to place single-photon emitters at desired positions on the wafer while obtaining a high creation yield and high spectral quality. After several cooling-down and warming-up cycles, there was no degradation of their optical properties. To allow for wafer-scale engineering of […]
Top 10 Science and Technology Inventions for the Week of February 24, 2023
01. Designing advanced ‘BTS’ materials for temperature and long-wave infrared sensing 02. How a record-breaking copper catalyst converts carbon dioxide into liquid fuels 03. U.S. unprepared for dangers posed by zoonotic diseases, new analysis concludes 04. Improving the performance of satellites in low Earth orbit 05. Nanoparticles self-assemble to harvest solar energy 06. New corrosion protection that repairs itself 07. Reactive fabrics respond to changes in temperature 08. Smooth sailing for electrons in graphene: Measuring fluid-like flow at nanometer resolution 09. Solid-state thermal transistor demonstrated 10. The switch – analogous to a transistor – made from a single fullerene molecule […]
Anti-dust tech paves way for self-cleaning surfaces
Phys.org February 22, 2023 Dust accumulation is detrimental to optical elements, electronic devices, and mechanical systems and is a significant problem in space missions and renewable energy deployment. A team of researchers in the US (UT Austin, industry) fabricated and demonstrated antidust nanostructured surfaces that can remove close to 98% of lunar particles solely via gravity. The structures are fabricated using a highly scalable nanocoining and nanoimprint process, where nanostructures with precise geometry and surface properties are patterned on polycarbonate substrates. The dust mitigation properties of the nanostructures were characterized using optical metrology, electron microscopy, and image processing algorithms to […]
Designing advanced ‘BTS’ materials for temperature and long-wave infrared sensing
Phys.org February 20, 2023 Replicating the molecular structure and functional motifs of biological compounds often provide clues to advance material designs and offers a blueprint for unprecedented functionalities. An international team of researchers (USA – Caltech, South Korea) has developed a flexible biomimetic thermal sensing (BTS) polymer that was designed to emulate the ion transport dynamics of a plant cell wall component, pectin. Using a simple yet versatile synthetic procedure, they engineered the physicochemical properties of the polymer by inserting elastic fragments in a block copolymer architecture, making it flexible and stretchable. The thermal response of the flexible polymer outperformed […]
How a record-breaking copper catalyst converts carbon dioxide into liquid fuels
Phys.org February 16, 2023 Cu enables CO2-to-multicarbon product (C2+) conversion. However, the nature of the active sites under operating conditions remains elusive. A team of researchers in the US (UC Berkely, Cornell University, Lawrence Livermore National Laboratory) has presented a comprehensive investigation of the structural dynamics during the life cycle of Cu nanocatalysts. A 7 nm Cu nanoparticle ensemble evolved into metallic Cu nanograins during electrolysis before complete oxidation to single-crystal Cu2O nanocubes following post-electrolysis air exposure. They confirmed the presence of metallic Cu nanograins under CO2 reduction conditions. Other tests suggested that metallic Cu, rich in nanograin boundaries, supports undercoordinated […]
Improving the performance of satellites in low Earth orbit
EurekAlert February 21, 2023 Although small satellites have a lot of potential due to their smaller size, they have lesser radiation shield and the deployable membrane attached to the main body for a large phased-array transceiver causing non-uniform radiation degradation across the transceiver. This affects the gain variation and performance of the satellite. To mitigate radiation degradation researchers in Japan created a phased-array transceiver with on-chip distributed radiation sensors which can detect the gain variation between the chips of the antenna. This was combined with current-sharing techniques to mitigate the gain variation and thus reduce the impact of non-uniform ionizing […]
Keeping drivers safe with a road that can melt snow, ice on its own
Science Daily February 16, 2023 In this study, a novel and economical green sustained-release microcapsule salt-storage anti-icing agent was prepared by researchers in China using solid waste porous sustained-release skeleton loading organic acetate salt as the core material and styrene-acrylic-acrylate copolymer P(AA-MA-BA-St) as the wall material, which have less corrosiveness and extended the release time. The blast furnace slag and NaHCO3 were selected as the sustained-release skeleton and corrosion inhibitors. The optimal conditions of the synthesis of vesicle wall materials were investigated: 3.8 wt % acrylic acid polymerized at 110 °C with 3 wt % AIBN and for 3.5 h, […]
Nanoparticles self-assemble to harvest solar energy
Science Daily February 21, 2023 Most disordered organic polymers are almost incapable of limiting the absorption in the desired cutoff wavelength range, which is detrimental to the design of selective absorbers. An international team of researchers (China, Singapore) reports a scalable selective absorber with a quasiperiodic nanostructure composed by an economical widespread surface self-assembly of densely arranged Fe3O4 nanoparticles, possessing a high-performance energy conversion for low-grade solar energy. By investigating the scale effect of the quasiperiodic densely arranged plasmonic nanostructure, a significant solar absorption >94% and ideal passive suppression of thermal emissivity <0.2 could be obtained simultaneously. With the synergy […]