Self-healing materials for robotics made from ‘jelly’ and salt

Science Daily  February 18, 2022 There are numerous challenges in the deployment of wearable devices with soft sensing technologies due to their poor resilience, high energy consumption, and omnidirectional strain responsivity. Researchers in the UK have developed a versatile ionic gelatin-glycerol hydrogel for soft sensing applications. The device is inexpensive and easy to manufacture, self-healable at room temperature, can undergo strains of up to 454%, presents stability over long periods of time, and is biocompatible and biodegradable. The material is ideal for strain sensing applications, with a linear correlation coefficient R2 = 0.9971 and a pressure-insensitive conduction mechanism. The experimental results show […]

Study raises new possibilities for triggering room-temperature superconductivity with light

Phys.org  February 9, 2022 An international team of researchers (South Korea, USA – SLAC National Accelerator Laboratory, Germany, Japan) explored a photoinduced normal state of YBCO through a charge density wave (CDW) with time-resolved resonant soft x-ray scattering, as well as a high magnetic field x-ray scattering. In the nonequilibrium state where people predict a quenched superconducting state based on the previous optical spectroscopies, they experimentally observed a similar analogy to the competition between superconductivity and CDW shown in the equilibrium state. Their results provide a critical clue that the characteristics of the photoinduced normal state show a solid resemblance […]

Tiny electrical vortexes bridge gap between ferroelectric and ferromagnetic materials

EurekAlert  February 9, 2022 An international team of researchers (UK, Ireland, USA – Argonne National Laboratory) created a thin film of the ferroelectric lead titanate sandwiched between layers of the ferromagnet strontium ruthenate, each about 4 nanometres thick. The structure of the combined layers revealed that the domains in the lead titanate were a complex topological structure of lines of vortexes, spinning alternately in different directions. Almost identical behaviour has also been seen in ferromagnets where it is known to be generated by the Dzyaloshinskii–Moriya interaction (DMi). According to the researchers the difference between ferromagnetism and ferroelectricity becomes less and […]

With a little help, new optical material assembles itself

Phys.org  February 4, 2022 To overcome a longstanding problem of molecular impurities in nanoscience a team of researchers in the US (MIT, UC Berkeley, Argonne National Laboratory) developed a new technique that coaxes diverse blends of polymers and nanoparticles into spontaneously forming tiny, nested rings within minutes of adding an impurity. They hypothesized that diversifying the blend’s composition can overcome these limitations. Increasing the number of components increases mixing entropy, leading to the dispersion of different components and, as a result, enhances interphase miscibility. The molecular migration would unlock the system’s entropy that helps to distribute the material’s building blocks, […]

Nano-architected material refracts light backward – an important step toward one day creating photonic circuits

Nanowerk  January 28, 2022 Negative refraction has not been observed in nature but was theorized to occur in artificially periodic materials. Researchers at Caltech designed, fabricated 3D photonic crystals (PhCs) capable of negative refraction in the mid-infrared. Band structure and equifrequency contours were calculated to inform the design of 3D polymer–germanium core–shell PhCs. They successfully characterized a polymer–Ge core–shell lattice and mapped its band structure, which were used to calculate the PhC refraction behavior. An analysis of wave propagation revealed that this 3D core–shell PhC refracts light negatively and possesses an effective negative index of refraction in the experimentally observed […]

Scientists weave atomically thin wires into ribbons

Phys.org  January 31, 2022 Using tungsten telluride nanowires researchers in Japan created bundles of wires deposited on a flat substrate and exposed to vapors of chalcogens like sulfur, selenium, and tellurium. With a combination of heat and vapor, the initially separate threads in the bundles were successfully woven together into narrow, atomically thin nanoribbons with a characteristic zigzag structure. By tuning the thickness of the original bundles, they could even choose whether these ribbons were oriented parallel to the substrate or perpendicular to it. By tuning the substrate on which the bundles are placed, they could control whether the ribbons […]

Tiny materials lead to a big advance in quantum computing

MIT News  January 27, 2022 An international team of researchers (USA – MIT, MIT Lincoln Laboratory, Japan) used hexagonal boron nitride to build a parallel-plate capacitor for a qubit. To fabricate the capacitor, they sandwiched hexagonal boron nitride between very thin layers of another van der Waals material, niobium diselenide and connected the capacitor to the existing structure and cooled the qubit to 20 millikelvins (-273.13 C). The resulting qubit was about 100 times smaller than what they made with traditional techniques on the same chip. The coherence time, or lifetime, of the qubit was only a few microseconds shorter […]

Bone growth inspired ‘microrobots’ that can create their own bone

Science Daily  January 17, 2022 Combining materials which together resemble the natural process of bone development an international team of researchers (Sweden, Japan) constructed a microrobot which can assume different shapes and change stiffness. They started with a gel material called alginate. On one side of the gel, they grew an electroactive polymer which changes its volume when a low voltage is applied, causing the microrobot to bend in a specified direction. On the other side of the gel, they attached biomolecules, that are important for bone development which allowed the soft gel material to harden. They demonstrated that the […]

New p-type, near-infrared transparent conducting thin films with better performance

Phys.org  January 19, 2022 The low conductivity of previous CuMO2 films obstructs the development of delafossite-based electronics. Researchers in China designed and fabricated a new p-type 4d transition metal Rh-based CuRhO2 film by a facile solution method. It has room-temperature conductivity as high as 735 S cm−1 which was achieved by substituting 10%Mg in Rh sites. The acceptor-doped CuRhO2 films exhibited high near-infrared transmittance of 85–60% with low room-temperature sheet resistance of 4.28–0.18 kΩ sq−1. The electronic structure, electrical transport mechanism, and intra-band excitation feature for the CuRhO2 film are unveiled. According to the researchers theoretical and experimental results contribute […]

Unexpected energy storage capability where water meets metal surfaces

Science Daily  January 19, 2022 Strong interaction of metal with water molecules leads to water chemisorption and accumulation of ions in the Helmholtz layer beyond expectation, resulting in a higher interface charge storage ability. An international team of researchers (Germany, Israel, France) extracted new physico-chemical information on the capacitance and structure of the electrical double-layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order-of-magnitude than predicted by the traditional mean-field models of the double-layer. Using molecular dynamics simulations, they investigated the possible relationship […]