The light-warping structures known as metamaterials have a new trick in their ever-expanding repertoire. Researchers at NIST have built a silver, glass and chromium nanostructure that can all but stop visible light cold in one direction while giving it a pass in the other. The device could someday play a role in optical information processing and in novel biosensing devices.
Materials science experts in North Carolina and China collaborated on work that drew inspiration from the structure of bones and bamboo. The team has found that by gradually changing the internal structure of metals, stronger, tougher materials can be created and customized for a wide variety of applications, from body armor to automobile parts. The gradient structure concept works on numerous metals, including stainless steel and nickel.
Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an emulsion, that is extremely hard to separate and can cause severe damage to ecosystems. A new membrane developed by Massachusetts Institute of Technology researchers can separate even these highly mixed fine oil-spill residues.
Using a scanning tunneling microscope to visualize the electronic structure of the oxygen sites within a superconductor, a Binghamton Univ. physicist and his colleagues say they have unlocked one key mystery surrounding high-temperature superconductivity. The team found a density wave with a d-orbital structure, which is a pattern new to this type of superconductor and they may be found in all cuprates.
Researchers at Lawrence Berkeley National Lab and the Univ. of Hawaii have uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. The finding could help combustion chemists make more-efficient, less-polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics.
Recent research at the Rice Univ. lab of materials scientist Pulickel Ajayan has discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms. But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength and applications that take advantage of their desirable electrical properties.
Physicists in Europe have solved a mystery that has puzzled scientists for half a century. it has long been known that the distance between the graphene oxide layers depends on the humidity, not the actual amount of water added. But now, with the help of powerful microscopes, it can be seen how distance between graphite oxide layers gradually increases when water molecules are added, and why this phenomenon occurs.
Researchers in Germany have produced a new material the size of a sugar cube that has a surface area equivalent to more than seven tennis courts. This novel type of nanofiber has a highly ordered and porous structure gives it an extraordinarily high surface-to-volume ratio and could be a key enabling technology for lithium-sulfur batteries.
A group of researchers from Russia, Belarus and Spain, including MIPT professor Yury Lozovik, have developed a microscopic force sensor based on carbon nanotubes. The device consists of two nanotubes placed so that their open ends are opposite to each other. Voltage of just 10 nA is then applied to the nanocircuit and force is measured by the change in position of the nanotubes.
For his doctoral dissertation, Yu Chen developed a novel way to fabricate superconducting nanocircuitry. However, the extremely small zinc nanowires he designed did some unexpected things, including demonstrating dissipation characteristics though only to be present in normal states. After long and careful work, which involved both experimental and theoretical efforts, researchers have found an explanation that fits.
The antibacterial properties of silver-coated textiles are popular in the fields of sport and medicine. A team in Switzerland has now investigated how different silver coatings behave in the washing machine, and they have discovered something important: textiles with nano-coatings release fewer nano-particles into the washing water than those with normal coatings.
An international team of physicists including researchers from the U.S. Naval Research Laboratory has used a scanning tunneling microscope to create quantum dots with identical, deterministic sizes. The perfect reproducibility of these dots opens the door to quantum dot architectures completely free of uncontrolled variations, an important goal for technologies from nanophotonics to quantum information processing.
You wouldn’t think that mechanical force could process nanoparticles more subtly than the most advanced chemistry. But researchers at Sandia National Laboratories have created a newly patented and original method that uses simple pressure to produce finer and cleaner results in forming silver nanostructures than do chemical methods, which are not only inflexible in their results but leave harmful byproducts.
Using world’s most powerful x-ray laser at the Linac Coherent Light Source in California, scientists have been watching as buckyballs disintegrate completely in less than 100 femtoseconds under the force of the powerful free-electron laser flashes. The study told them something important, too: they can theoretically and reliable predict the way these miniature soccer balls will explode. This is important for simulation efforts.
Scientists at the Univ. of California, Riverside have constructed liquid crystals with optical properties that can be instantly and reversibly controlled by an external magnetic field. Unlike conventional liquid crystals, which rotate and align themselves when an electric field is applied, the new crystals are essentially a liquid dispersion of magnetic nanorods.
What is believed to be the smallest force ever measured has been detected by researchers with the Lawrence Berkeley National Laboratory and the Univ. of California, Berkeley. Using a combination of lasers and a unique optical trapping system that provides a cloud of ultracold atoms, the researchers measured a force of approximately 42 yoctonewtons.
In wind farms across North America and Europe, sleek turbines equipped with state-of-the-art technology convert wind energy into electric power. But tucked inside the blades of these feats of modern engineering is a decidedly low-tech core material: balsa wood.
Wrinkles, creases and folds are everywhere in nature, from the surface of human skin to the buckled crust of the Earth. They can also be useful structures for engineers. Wrinkles in thin films, for example, can help make durable circuit boards for flexible electronics. A newly developed mathematical model could help engineers control the formation of wrinkle, crease and fold structures in a wide variety of materials.
Using high speed video, transmission electron microscopy, spectrometry, energy dispersive x-ray spectroscopy, and computer modeling, a Univ. of California, Berkeley graduate student has unraveled the mystery of the disco clams flashing “lips”. Most people assumed the glowing mantle was the result of bio-luminescence, but Lindsey Dougherty has found it is caused by something else entirely.
An international team has developed an elegant method for producing self-organized and functionalized carbon nanolayers and equipping them chemically with a range of functions. The effort depended on the development of a special compound, the molecules of which were aligned perfectly in parallel to each other in a single self-organized layer, like the bristles on a brush.
Oak Ridge National Laboratory has launched the Institute for Functional Imaging of Materials to accelerate discovery, design and deployment of new materials. The institute will meld world-class capabilities in imaging, high-performance computing, materials science and other scientific disciplines to probe materials.
There’s a story about how the modern golf ball, with its dimpled surface, came to be: In the mid-1800s, it’s said, new golf balls were smooth, but became dimpled over time as impacts left permanent dents. Smooth new balls were typically used for tournament play, but in one match, a player ran short, had to use an old, dented one, and realized that he could drive this dimpled ball much further than a smooth one.
Current drug delivery systems used to administer chemotherapy to cancer patients typically release a constant dose of the drug over time, but a new study challenges this "slow and steady" approach and offers a novel way to locally deliver the drugs "on demand," as reported in the Proceedings of the National Academy of Sciences.
The electrons in graphene behave as “massless” particles, yet these electrons also seem to have dual personalities. Phenomena observed in the field of graphene plasmonics suggest that when the electrons move collectively, they must exhibit mass. After two years of effort, researchers at Harvard Univ. have successfully measured the collective mass of “massless” electrons in motion in graphene.
According to researchers, a simple, scalable method of making strong, stretchable graphene oxide fibers that are easily scrolled into yarns and have strengths approaching that of Kevlar is possible. An international collaboration has recently produced graphene oxide yarn fibers much stronger than other carbon fibers.