Metamaterials offer tantalizing future prospects such as high-resolution optical microscopes and superfast optical computers. To realize the vast potential of metamaterials, however, scientists will need to hone their understanding of the fundamental physics behind them. This will require accurately predicting nonlinear optical properties.
Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism. A team of scientists designed methods to validate their 2012 discovery that combined polyethylene glycol-hydrophilic carbon clusters could quickly stem the process of overoxidation that can cause damage in the minutes and hours after an injury.
Artists, print designers and interior decorators have long had access to a broad palette of paint and ink colors for their work. Now, researchers have created a broad color palette of electrochromic polymers, materials that can be used for sunglasses, window tinting and other applications that rely on electrical current to produce color changes.
Univ. of California, Berkeley scientists have found the mechanism by which titanium, prized for its high strength-to-weight ratio and natural resistance to corrosion, becomes brittle with just a few extra atoms of oxygen. The discovery has the potential to open the door to more practical, cost-effective uses of titanium in a broader range of applications.
A novel approach to growing nanowires promises a new means of control over their light-emitting and electronic properties. In a recent issue of Nano Letters, scientists from Lawrence Berkeley National Lab demonstrated a new growth technique that uses specially engineered catalysts. These catalysts, which are precursors to growing the nanowires, have given scientists more options than ever in turning the color of light-emitting nanowires.
Proteins are the building blocks of all living things, and they exist in virtually unlimited varieties, most of whose highly complex structures have not yet been determined. Those structures could be key to developing new drugs or to understanding basic biological processes. But figuring out the arrangement of atoms in these complicated, folded molecules usually requires getting them to form crystals large enough to be observed in detail.
When a metal tube lines an oil well thousands of feet below the surface of the ocean, that metal had better be solid and reliable. Unfortunately, the environment in such deep wells is often rich in hydrogen, a gas that can penetrate high-tech alloys and make them brittle, making fractures and leaks more likely. Now researchers have figured which characteristics of a metal structure foster this embrittlement in the presence of hydrogen.
While the mysterious, unseen forces magnets project are now (mostly) well understood, they can still occasionally surprise us. For instance, thin films of cobalt have been observed to spontaneously switch their poles: something that typically doesn’t happen in the absence of an external magnetic field. Physicists at NIST and the Univ. of Maryland have measured this phenomenon on the largest scale yet.
Researchers at Virginia Commonwealth Univ. and universities in China and Japan have discovered a new structural variant of carbon called "penta-graphene", a very thin sheet of pure carbon that has a unique structure inspired by a pentagonal pattern of tiles found paving the streets of Cairo.
Lawrence Berkeley National Laboratory researchers have developed a nano-sized optical antenna that can greatly enhance the spontaneous emission of light from atoms, molecules and semiconductor quantum dots. This advance opens the door to light-emitting diodes (LEDs) that can replace lasers for short-range optical communications, including optical interconnects for microchips, plus a host of other potential applications.
Far from being a defect, a winding thread of odd rings at the border of two sheets of graphene has qualities that may prove valuable to manufacturers, according to Rice Univ. scientists. Graphene rarely appears as a perfect lattice of chicken wire-like six-atom rings. When grown via chemical vapor deposition, it usually consists of “domains,” or separately grown sheets that bloom outward from hot catalysts until they meet up.
The editors of R&D Magazine are looking for speakers to participate in a webinar on “Using Multiple Materials in 3D Printing.” Candidates are asked to give a 15-min PowerPoint-based talk over the phone on their experiences in fabricating 3D printed products using multiple materials or developing the processes and/or technologies to accomplish this.
The lowly roundworm is the star of an ambitious Rice Univ. project to measure the toxicity of nanoparticles. The low-cost, high-output study measures the effects of many types of nanoparticles not only on individual organisms but also on entire populations. The researchers tested 20 types of nanoparticles and determined that five, including the carbon-60 molecules (“buckyballs”) discovered at Rice in 1985, showed little to no toxicity.
The most popular next-generation solar cells under development may have a problem: The top layer is full of tiny pinholes, researchers at the Okinawa Institute of Science and Technology Graduate Univ. in Japan have found. The majority of high-performance solar cells under development use a combination of materials including perovskite and spiro-MeOTAD.
Efficiency is big in the tiny world of thermoelectric nanowires. Researchers at Sandia National Laboratories say better materials and manufacturing techniques for the nanowires could allow carmakers to harvest power from the heat wasted by exhaust systems or lead to more efficient devices to cool computer chips.
If you can’t find the ideal material, then design a new one. Northwestern Univ.’s James Rondinelli uses quantum mechanical calculations to predict and design the properties of new materials by working at the atom-level. His group’s latest achievement is the discovery of a novel way to control the electronic band gap in complex oxide materials without changing the material’s overall composition.
Researchers at the Univ. of Liverpool and Univ. College London have shown a new way to use a single molecule as a magnetic field sensor. In a study, published in Nature Nanotechnology, the team shows how magnetism can manipulate the way electricity flows through a single molecule, a key step that could enable the development of magnetic field sensors for hard drives that are a tiny fraction of their present size.
Engineers are shining new light on an emerging family of solar-absorbing materials that could clear the way for cheaper and more efficient solar panels and LEDs. The materials, called perovskites, are particularly good at absorbing visible light, but had never been studied in their purest form: as perfect single crystals.
Imagine eyeglasses that can go quickly from clear to shaded and back again when you want them to, rather than passively in response to changes in light. Scientists report a major step toward that goal, which could benefit pilots, security guards and others who need such control, in ACS Applied Materials & Interfaces.
In Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that allows growth of highly efficient and reproducible solar cells from large-area perovskite crystals. The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%.
In today’s world, in which the threat of terrorism looms, there is an urgent need for fast, reliable tools to detect the release of deadly chemical warfare agents (CWAs). In ACS Macro Letters, scientists are reporting new progress toward thin-film materials that could rapidly change colors in the presence of CWAs.
After undergoing surgery to remove diseased sections of the colon, up to 30% of patients experience leakage from their sutures, which can cause life-threatening complications. Many efforts are under way to create new tissue glues that can help seal surgical incisions and prevent such complications; now, a new study reveals that the effectiveness of such glues hinges on the state of the tissue in which they are being used.
Researchers at Chalmers Univ. of Technology have discovered that the insulation plastic used in high-voltage cables can withstand a 26% higher voltage if nanometer-sized carbon balls are added. This could result in enormous efficiency gains in the power grids of the future, which are needed to achieve a sustainable energy system.
A potential avenue to quantum computing currently generating quite the buzz in the high-tech industry is “valleytronics,” in which information is coded based on the wavelike motion of electrons moving through certain 2-D semiconductors. Now, a promising new pathway to valleytronic technology has been uncovered by researchers with the Lawrence Berkeley National Laboratory.
Friction impacts motion, hence the need to control friction forces. Currently, this is accomplished by mechanistic means or lubrication, but experiments conducted by researchers at Oak Ridge National Laboratory have uncovered a way of controlling friction on ionic surfaces at the nanoscale using electrical stimulation and ambient water vapor.