Scientists have been able to manufacture 3-D isotropic metamaterials, but up to now only on a very small scale. Now, in a significant breakthrough, scientists from RIKEN, in collaboration with colleagues in Taiwan, have succeeded in creating a large metamaterial up to 4-mm-square in size that is essentially isotropic, using a type of metamaterial element called a split-ring resonator.
When a solid material is immersed in a liquid, the liquid immediately next to its surface differs from that of the bulk liquid at the molecular level. This interfacial layer is critical to our understanding of a diverse set of phenomena. When the solid surface is charged, it can drive further changes in the interfacial liquid. However, elucidating the molecular structure at the solid-liquid interface under these conditions is difficult.
An international team of scientists have become the first to successfully reach temperatures below -272.15 C, which is just above absolute zero, using magnetic molecules. The effort, which avoids the use of helium, depends on a form of gadolinium that appropriately has a structure resembling a snowflake.
A few short years ago, the idea of a practical manufacturing process based on getting molecules to organize themselves in useful nanoscale shapes seemed far-fetched. Recent work at NIST, Massachusetts Institute of Technology and IBM Almaden Research Center suggest this capability isn’t far off, however, by demonstrating self-assembly of thin films on a polymer template that creates precise rows just 10 nm wide.
Scientists at Ames Laboratory have developed deeper understanding of the ideal design for mesoporous nanoparticles used in catalytic reactions, such as hydrocarbon conversion to biofuels. The research will help determine the optimal diameter of channels within the nanoparticles to maximize catalytic output.
Researchers in Australia have discovered that nano-sized fragments of graphene have the ability to speed up the rate of chemical reactions. The finding is significant, say researchers, because it suggested that graphene might have potential applications in catalyzing chemical reactions of industrial importance.
Scientists at Oak Ridge National Laboratory have discovered exceptional properties in a garnet material that could enable development of higher-energy battery designs. The team used electron microscopy to take an atomic-level look at a cubic garnet material called LLZO. The researchers found the material to be highly stable in a range of aqueous environments, making the compound a promising component in new battery configurations.
Research by an international team of scientists has uncovered a new, unpredicted behavior in a copper oxide material that becomes superconducting at relatively high temperatures. This new phenomenon presents a challenge to scientists seeking to understand its origin and connection with high-temperature superconductivity. Their ultimate goal is to design a superconducting material that works at room temperature.
Several types of plastic pipes in eco-friendly green buildings in the U.S. have been found to leach chemicals into drinking water that can cause odors and sometimes exist at levels that may exceed health standards. Purdue Univ. engineering professor Andrew Whelton will detail these findings during the 2014 U.S. Green Building Council’s Greenbuild International Conference & Exposition on Oct. 24 in New Orleans.
Research at Oak Ridge National Laboratory has cracked one mystery of glass to shed light on the mechanism that triggers its deformation before shattering. The study improves understanding of glassy deformation and may accelerate broader application of metallic glass, a moldable, wear-resistant, magnetically exploitable material that is thrice as strong as the mightiest steel and ten times as springy.
Microscopic particles that bind under low temperatures will melt as temperatures rise to moderate levels, but re-connect under hotter conditions, a team of New York Univ. scientists has found. Their discovery points to new ways to create "smart materials," cutting-edge materials that adapt to their environment by taking new forms, and to sharpen the detail of 3-D printing.
Personal electronics such as cell phones and laptops could get a boost from some of the lightest materials in the world. Lawrence Livermore National Laboratory researchers have turned to graphene aerogel for enhanced electrical energy storage that eventually could be used to smooth out power fluctuations in the energy grid.
Graphene’s exotic properties can be tailored by cutting large sheets down to ribbons of specific lengths and edge configurations. But this “top-down” fabrication approach is not yet practical, because current lithographic techniques always produce defects. Now, scientists from the U.S. and Japan have discovered a new “bottom-up” self-assembly method for producing defect-free graphene nanoribbons with periodic zigzag-edge regions.
Researchers in Japan have developed a new yet simple technique called "diffusion driven layer-by-layer assembly" to construct graphene into porous 3-D structures for applications in devices such as batteries and supercapacitors. The new method borrowed a principle from polymer chemistry, known as interfacial complexation, to allow graphene oxide to form a stable composite layer with an oppositely charged polymer.
Researchers at Japan’s National Institute of Advanced Industrial Science and Technology have synthesized an atomic chain in which two elements, cesium and iodine, are aligned alternately inside a carbon nanotube. Analyzed using electron microscopy and spectroscopy, the invention could shed light on the adsorption mechanisms of radioactive elements.
Univ. of Texas at Arlington engineering professors have received an Air Force grant to examine the material surface at the micro- and nano-scale level that will provide clues for predicting fatigue in aircraft parts. The new approach will rely on a scanning whitelight interferometric surface profiler integrated with a compact mechanical tester and an electron backscatter diffraction module to deliver in-situ 3-D surface profiling.
The phase-out of traditional incandescent bulbs in the U.S. and elsewhere, as well as a growing interest in energy efficiency, has given LED lighting a sales boost. That trend could be short-lived as key materials known as rare earth elements become more expensive. Scientists at Rutgers Univ., however, have now designed new materials for making household LED bulbs without using these ingredients.
Scientists report that they have made the first experimental observation of piezoelectricity and the piezotronic effect in an atomically thin material, molybdenum disulfide. This finding has resulted in a unique electric generator and could point the way to mechanosensation devices that are optically transparent, extremely light, and very bendable and stretchable.
Iron catalysts remove oxygen inexpensively, but are susceptible to rust or oxidation in biofuel production. Precious metals that resist corrosion are even less efficient at removing oxygen. But adding just a touch of palladium to the iron produces a catalyst that quickly removes oxygen atoms, easily releases the desired products, and doesn't rust, according to scientists at Pacific Northwest National Laboratory and Washington State Univ.
Using 3-D printing and novel semiconductors, researchers at Oak Ridge National Laboratory have created a power inverter that could make electric vehicles lighter, more powerful and more efficient. At the core of this development is wide bandgap material made of silicon carbide with qualities superior to standard semiconductor materials.
Officials at a Chicago-based startup, Sagamore-Adams Laboratories LLC, say innovations discovered in Purdue University's School of Nuclear Engineering are being commercialized to address challenges in improving radiation detection and making sealants and adhesives safer. They have developed technology that could lead to radiation sensors that cost less and provide better information than traditional sensors.
Swedish and Chinese researchers have recently shown how a unique nano-alloy composed of palladium nano-islands embedded in tungsten nanoparticles creates a new type of catalysts for highly efficient oxygen reduction, the most important reaction in hydrogen fuel cells. Their results are published in the scientific journal Nature Communications.
When trying to design a mechanical system to last as long as possible, scientists and engineers have to find ways of overcoming friction. While researchers have found many materials that help to reduce friction, conventional lubricants often have chemical limitations. A recent analysis at Argonne National Laboratory has identified the properties of a newer, wear-resistant substance that works in a broader range of environments.
Researchers at Oak Ridge National Laboratory have obtained the first direct observations of atomic diffusion inside a bulk material. The research, which could be used to give unprecedented insight into the lifespan and properties of new materials, is published in Physical Review Letters.
Developing the cloak of invisibility would be wonderful, but sometimes simply making an object appear to be something else will do the trick, according to Penn State Univ. engineers. To do this, they employ what they call "illusion coatings," which are made of a thin flexible substrate with copper patterns designed to create the desired result. The metamaterial coatings can function normally while appearing as something else.