Phys.org December 13, 2021 The ions released from the metal’s surface are toxic to bacterial cells. But this process is slow when standard copper is used. Researchers in Australia used a special copper mold casting process to make the alloy, arranging copper and manganese atoms into specific formations. The manganese atoms were then removed from the alloy using dealloying leaving pure copper full of tiny microscale and nanoscale cavities in its surface. The resulting copper is composed of comb-like microscale cavities and within each tooth of the comb structure are much smaller nanoscale cavities; it has a massive active surface […]
Tag Archives: Advanced materials
Unbreakable bionic glove made from silk for human-machine-interfacing
Nanowerk December 14, 2021 An international team of researchers (Denmark, Finland) has designed a new electronic material called CareGum by mixing silk fibroin and reduced graphene oxide. They used a phenolic glue to facilitate sacrificial and hierarchical hydrogen bonds. The hierarchal bonding scheme gives rise to high mechanical toughness, record-breaking elongation capacity of ≈25 000%, excellent conformability to arbitrary and complex surfaces, 3D printability, a tenfold increase in electrical conductivity, and a fourfold increase in Young’s modulus compared to its pristine counterpart. Since its conductivity is based on ions, CareGum can convey information over longer distances than rigid electronics based […]
Transforming materials with light
Nanowerk December 8, 2021 Although there are strategies to drastically alter electronic and magnetic properties by optically inducing non-trivial band topologies, emergent spin interactions and superconductivity, methods of coherently engineering optical properties on demand are far less understood. An international team of researchers (Caltech, UC Santa Barbara, South Korea) has demonstrated coherent control and giant modulation of optical nonlinearity in a van der Waals layered magnetic insulator, manganese phosphorus trisulfide (MnPS3). They observed a coherent on–off switching of its optical second harmonic generation efficiency on the timescale of 100 femtoseconds with no measurable dissipation. At driving electric fields of the order […]
Magnetene: Graphene-like 2D material leverages quantum effects to achieve ultra-low friction
Phys.org November 17, 2021 Low-friction interfaces in 2D materials are often attributed to van der Waals (vdW) bonding of 2D materials, and nanoscale and quantum confinement effects can also act to modify the atomic interactions of a 2D material producing unique interfacial properties. An international team of researchers (Canada, USA – Rice University) has demonstrated low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials. They found that this low friction is due to 2D confinement effects of minimized potential energy surface corrugation, lowered valence states reducing […]
New material could be two superconductors in one
MIT News November 15, 2021 An international team of researchers (USA – MIT, Rutgers University, National High Magnetic Field Laboratory, Harvard University, Japan) synthesized layered superconductor Ba6Nb11S28. Instead of via one electron a superconductor carries charge by two electrons bound together in a Cooper pair. By applying an in-plane magnetic field, they observed an abrupt, partial suppression of diamagnetism below the upper critical magnetic field, which is suggestive of an emergent phase within the superconducting state. It turns out this kind of superconductor can be manipulated to form a variety of unusual patterns as Cooper pairs move between Landau levels. […]
Electron family creates previously unknown state of matter
Science Daily November 5, 2021 What distinguishes a superconducting state from a normal state is a spontaneously broken symmetry corresponding to the long-range coherence of pairs of electrons, leading to zero resistivity and diamagnetism. An international team of researchers (Germany, Sweden, Japan, France) was investigating the superconducting metal Ba1-xKxFe2As2 from the class of iron pnictides when they discovered that four electrons instead of two were forming a bond. It was scrutinized for two years using seven different methods to confirm the result. All data were consistent with the same result. Thus, they concluded that the four-particle electron family in certain […]
Ultra-thin crystals as light sources in lasers
Nanowerk November 8, 2021 Previously an international team of researchers (Germany, Russia, USA – Arizona State University, Japan) reported that a layer of the semiconductor material molybdenum diselenide generated laser light at cryogenic temperatures. Now they created the same effect at room temperature in exciton-polaritons. If sufficient exciton-polaritons are generated, they merge into a macroscopic quantum state. A sudden increase in light emission from the sample indicates that this transformation has taken place. The resulting radiation has only a single wavelength and displays coherence. To demonstrate the effect, they placed thin layers of tungsten diselenide between special mirrors. By studying the […]
Creating an artificial material that can sense, adapt to its environment
Phys.org November 2, 2021 A team of researchers in the US (University of Missouri, University of Chicago) has developed an artificial material that uses a computer chip to control or manipulate the processing of information that’s needed to perform the requested actions, then uses the electrical power to convert that energy into mechanical energy. The material incorporates three main functions also displayed by materials found in nature—sensing; information processing; and actuation, or movement. They control how the material responds to changes in external stimuli found in its surroundings. According to the researchers their approach, built on symmetries and conservation laws, […]
Electrical control over designer quantum materials
Science Daily October 22, 2021 Recently engineered stacks of two-dimensional materials have emerged as a powerful platform for studying quantum correlations between electronic states. However, the strength of the interaction between the quantum states is typically fixed once a stack is fabricated. An international team of researchers (Switzerland, Japan) demonstrated that they can induce Feshbach resonance in their system allowing to tune the interaction strength between quantum entities by bringing them into resonance with a bound state. In their case the bounds states were between an exciton in one layer and a hole in the other layer. It turns out […]
Engineers develop flexible, self-healing material to protect steel from the elements
Phys.org October 22, 2021 An international team of researchers (USA – Rice University, South Dakota School of Mines and Technology, SUNY Buffalo, George Washington University, Rensselaer Polytechnic Institute, Canada) has designed a lightweight sulfur–selenium (S–Se) alloy with high stiffness and ductility that can serve as an excellent corrosion-resistant coating with protection efficiency of ≈99.9% for steel in a wide range of diverse environments. S–Se coated mild steel showed a corrosion rate that is 6–7 orders of magnitude lower than bare metal in abiotic (simulated seawater and sodium sulfate solution) and biotic (sulfate-reducing bacterial medium) environments. The coating is strongly adhesive, […]