EurekAlert April 13, 2021 Rose petals have a matt and at the same time rich color. The outer tissue of its petals, the epidermis, consists of densely packed microstructures, additionally ribbed by nanostructures. With these structures, the rose manages to couple all incident light into the cells – only the colored light escapes again. Researchers in Germany combined micro- and nanostructure to develop an anti-reflective film that replicates the epidermis of rose petals. The film increases the yield of solar modules by up to ten percent. Posters, display panels, traffic signs, furniture, packaging, facades, and many other applications also benefit […]
Category Archives: Advanced materials
Transforming circles into squares
Science Daily April 14, 2021 The fundamental topology of cellular structures can profoundly affect their acoustic, electrical, chemical, mechanical, and optical properties, as well as heat, fluid, and particle transport. In the previous techniques the resulting structures generally preserve the defining connectivity features of the initial topology. Researchers at Harvard University have developed a two-tiered dynamic strategy that achieves systematic reversible transformations of the fundamental topology of cellular microstructures, which can be applied to a wide range of materials and geometries. The approach requires exposing the structure to a selected liquid that can first infiltrate and plasticize the material at […]
Big breakthrough for ‘massless’ energy storage
Science Daily March 22, 2021 Stiff and strong batteries that use solid‐state electrolytes and resilient electrodes and separators are generally lacking. Researchers in Sweden have demonstrated a structural battery composite with unprecedented multifunctional performance featuring an energy density of 24 Wh kg−1 and an elastic modulus of 25 GPa and tensile strength exceeding 300 MPa. The structural battery is made from multifunctional constituents, where reinforcing carbon fibers (CFs) act as electrode and current collector. A structural electrolyte is used for load transfer and ion transport and a glass fiber fabric separates the CF electrode from an aluminum foil‐supported lithium–iron–phosphate positive electrode. The battery performs […]
Researchers make breakthrough in solar cell materials
Phys.org March 12, 2021 An international team of researchers (USA – Clemson University, Los Alamos National Laboratory, University of Alabama, China) observed the ultrafast dynamics of trapped carriers in organic methyl ammonium lead halide perovskite thin films by ultrafast photocurrent spectroscopy. Upon ultrafast laser excitation, trapped carriers followed a phonon assisted tunneling mechanism and a hopping transport mechanism along ultra-shallow to shallow trap states ranging from 1.72–11.51 millielectronvolts. They validated the transport mechanisms by highlighting trap state dynamics, including trapping rates, de-trapping rates and trap properties, such as trap density, trap levels, and capture-cross sections. The work establishes a foundation […]
Team creates new ultralightweight, crush-resistant tensegrity metamaterials
Phys.org March 11, 2021 Catastrophic collapse of materials and structures is the inevitable consequence of a chain reaction of locally confined damage. A-team of researchers in the US (UC Irvine, Georgia Institute of Technology) created mechanical metamaterials that delocalize deformations to prevent failure. They used direct laser writing technique to generate elementary cells sized between 10 and 20 microns which were built up into eight-unit supercells that could be assembled with others to make a continuous structure. They showed that failure resistance is up to 25‐fold enhancement in deformability and orders of magnitude increased energy absorption capability without failure over […]
Scientists have synthesized a new high-temperature superconductor
Phys.org March 10, 2021 An international team of researchers (Russia, USA – University of Chicago, Spain, Italy, China) performed theoretical and experimental research on yttrium hydride (YH6), one among the three highest-temperature superconductors known to date. All these hydrides reach their maximum superconductivity temperatures at very high pressures. The current challenge is to attain room-temperature superconductivity at lower pressures. In the case of YH6, the agreement between theory and experiment is rather poor. For example, the critical magnetic field observed in the experiment is 2 to 2.5 times greater as compared to theoretical predictions. This is the first-time scientists encounter such […]
Engineering the boundary between 2D and 3D materials
MIT News February 26, 2021 The atomic structure at the interface between 2D and 3D materials influences properties such as contact resistance, photo-response, and high-frequency electrical performance. An international team of researchers (USA – MIT, Harvard University, Canada) used epitaxially aligned MoS2/Au as a model system to demonstrate the use of advanced scanning transmission electron microscopy combined with a geometric convolution technique in imaging the crystallographic moiré pattern at the 2D/3D interface. This moiré period is often hidden in conventional electron microscopy, where the Au structure is seen in projection. They showed that charge density is modulated according to the […]
An intelligent soft material that curls under pressure or expands when stretched
Nanowerk February 24, 2021 Existing perceptive soft actuators require complex integration and coupling between the discrete functional units to achieve autonomy and intelligently interact with humans and the environment. Researchers in China have developed actuators with embodied sensing, actuation, and control at the single-unit level by synergistically harnessing the mechanosensing and electrothermal properties of liquid metal (LM) to actuate the thermally responsive liquid crystal elastomer (LCE). They created multifunctional LM circuits on the LCE surface using a simple and facile methodology based on magnetic printing. The fluidic LM circuit can be utilized as a conformable resistive heater, and a sensory […]
Magnetic effect without a magnet
Nanowerk February 22, 2021 An international team of researchers (Austria, Switzerland, Canada, USA – Rice University) found Ce3Bi4Pd3 produced a giant Hall effect in the total absence of any magnetic field and showed that the strange phenomenon is due to the complicated interaction of the electrons. Specific symmetries of the atoms determine the dispersion relation, the relationship between the energy of the electrons and their momentum. This complex interaction results in phenomena that mathematically look as if there are magnetic monopoles in the material which do not exist in this form in nature. But it has the effect of a […]
Breakthrough material can protect satellites from ultraviolet radiation and atomic oxygen in low-Earth orbit
Phys.org February 16, 2021 Atomic oxygen is created when O2 molecules break apart, a process made easier in space because of the abundance of ultraviolet radiation affecting the structural integrity of space structures. An international team of researchers (UK, Germany) has developed a nano-barrier that bonds to the surface of polymer or composite materials, protecting them from erosion in low-Earth orbit without disrupting the functional performance of the space structure. The multilayered protection barrier deposited via a custom-built plasma-enhanced chemical vapor deposition system is designed to deposit all necessary layers without breaking vacuum to maximize the adhesion to the surface […]