Science Daily December 6, 2022 The transfer of wave momentum is a fundamental mechanism for contactless manipulation, yet the rules of conventional scattering intrinsically limit the radiation force based on the shape and the size of the manipulated object. Researchers at the University of Minnesota showed that this intrinsic limit can be broken for acoustic waves with subwavelength metasurfaces. Harnessing anomalous metasurface scattering, they demonstrated self-guidance, where a metasurface object is autonomously guided by an acoustic wave, and tractor beaming, where a metasurface object is pulled by the wave. According to the researchers their results show that bringing the metasurface […]
Single-electron devices could manage heat flow in electronic components
Nanowerk December 8, 2022 Previous heat engines based on quantum dots have used reservoirs of electrons at different temperatures. An international team of researchers (Japan, Germany) has fabricated a nanoscale ‘heat engine’ that uses a property of spin as the effective working medium. They confined electrons using electric fields generated at surface metal electrodes on a gallium arsenide surface. The device had two interlinked quantum dots and a built-in charge sensor to passively monitor what was going on within the double quantum dot. A third quantum dot was used to control the double quantum dot’s thermal environment. According to the […]
Soft robot detects damage, heals itself
Science Daily December 7, 2022 Researchers at Cornell University have introduced damage intelligent soft-bodied systems via a network of self-healing light guides for dynamic sensing (SHeaLDS). Exploiting the intrinsic damage resilience of light propagation in an optical waveguide, in combination with a tough, transparent, and autonomously self-healing polyurethane urea elastomer, SHeaLDS enabled damage resilient and intelligent robots by self-healing cuts as well as detecting this damage and controlling the robot’s actions accordingly. With optimized material and structural design for hyperelastic deformation of the robot and autonomous self-healing capacity, SHeaLDS provided reliable dynamic sensing at large strains with no drift or […]
Unexpected speed-dependent friction with graphene
Nanowerk, December 6, 2022 Graphene is being examined with a view to potential use as a lubricating layer. If it is applied to a platinum surface, it has a significant impact on the measurable friction forces. An international team of researchers (Israel, Switzerland) has reported that, in this instance, the friction depends on the speed at which the tip of an atomic force microscope (AFM) is moved across the surface. In conjunction with the platinum substrate, graphene no longer forms only the hexagonal honeycomb pattern of carbon atoms and instead forms Moiré superlattices. The surface is then no longer completely […]
Top 10 Science and Technology Inventions for the Week of December 2, 2022
01. Cranking the Power on Radar Capabilities 02. Electron pairing in quantum dots as a new approach to qubit research 03. Flexible strain sensor enabled by carbon nanofibers can ‘read lips’ 04. How to fire projectiles through materials without breaking anything 05. Microscopic chains that mimic DNA 06. New device can control light at unprecedented speeds 07. A scalable quantum memory with a lifetime over 2 seconds and integrated error detection 08. Scientists construct novel quantum testbed one atom at a time 09. Seeding the oceans with iron-rich fertilizer nanoparticles to store excess carbon dioxide 10. Stripping carbon from the […]
Cranking the Power on Radar Capabilities
DARPA November 23, 2022 Technologies for Heat Removal in Electronics at the Device Scale (THREADS) aims to overcome the thermal limits inherent to internal circuitry operations in general, and to critical power-amplifying functions specifically. THREADS targets thermal management challenges at the transistor level. Central to this effort will be reducing the thermal resistance involved in dissipating internal heat without degrading performance or increasing the footprint of the transistors key to advancing radar capabilities. Wide bandgap transistors, such as gallium nitride (GaN), were developed specifically to improve output density in power amplifiers and further order-of-magnitude increase in power output is possible […]
Electron pairing in quantum dots as a new approach to qubit research
Phys.org November 25, 2022 Materials with intrinsic p-wave superconductivity, hosting Cooper pairs made of equal-spin electrons, have not been conclusively identified, nor synthesized, despite promising progress. Instead, engineered platforms where s-wave superconductors are brought into contact with magnetic materials have shown convincing signatures of equal-spin pairing. Researchers in the Netherlands have directly measured equal-spin pairing between spin-polarized quantum dots. The pairing is proximity-induced from an s-wave superconductor into a semiconducting nanowire with strong spin–orbit interaction. They demonstrated such pairing by showing that breaking a Cooper pair can result in two electrons with equal spin polarization. Their results demonstrated controllable detection […]
Flexible strain sensor enabled by carbon nanofibers can ‘read lips’
Phys.org November 29, 2022 While high sensitivity and wide working range are desired key parameters for a strain sensor, they are usually contrary to each other to be achieved on the same sensor due to the tight structure dependence of both. Researchers in China used an integrated membrane containing both parallel aligned and randomly aligned carbon nanofibers (CNFs) to design a flexible strain sensor with high sensitivity and wide strain detection range. The parallel aligned CNF membrane (p-CNF) exhibited a low strain detection limit and high sensitivity, while the random aligned CNF membrane (r-CNF) exhibits a large strain detection range. […]
How to fire projectiles through materials without breaking anything
Nanowerk November 28, 2022 Researchers in Austria bombarded ultrathin materials with highly charged ions to explain why sometimes the projectile penetrates the material layer without any noticeable change in the material and sometimes the material layer around the impact site is also completely destroyed. They found that it is not the momentum of the projectile that is mainly responsible for the holes, but its electric charge. When an ion with multiple positive charge hits the material layer, it attracts a larger number of electrons and takes them with it leaving a positively charged region in the material layer. Graphene’s high […]
Microscopic chains that mimic DNA
Phys.org November 29, 2022 DNA conformation is well understood for biological processes. An international team of researchers (Austria, Poland, Italy) focused on chains interlocking the rings and observed their behavior and how they could be used to design innovative materials. They showed that circular polycatenanes have physical and geometrical properties very similar to those of double stranded DNA rings. They demonstrated that the connection of local and global properties holds for these structures too, that is there is a connection between what occurs in a part of the structure and in its whole. The amount of twist of the polycatenanes […]