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.
SiEnergy Systems, an Allied Minds company commercializing low temperature thin film solid oxide fuel cell (SOFC) technology from Harvard University, has announced that it has been selected for $2.65 million in funding from Advanced Research Projects Agency-Energy (ARPA-E). SiEnergy has develop innovative and unique hybrid electrochemical system that performs as both fuel cell and battery.
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.
In semiconductor-based components, high mobility of charge-carrying particles is important. In organic materials, however, it is uncertain to what degree the molecular order within the thin films affects the mobility and transport of charge carriers. Using a new imaging method, researchers have shown that thin-film organic semiconductors contain regions of structural disorder that could inhibit the transport of charge and limit efficiency.
Normally, keeping glass clean and clear depends on repelling or wiping away water droplets. Or a coating attached to help do this. But researchers in Singapore have discovered that doing just the opposite, collecting water, is the key to keeping a surface clear. Their superhydrophilic coating attracts water to create a uniform, thin, transparent layer.
Scientists seeking ways to engineer the assembly of tiny particles measuring just billionths of a meter have achieved a new first: the formation of a single layer of nanoparticles on a liquid surface where the properties of the layer can be easily switched. Understanding the assembly of such nanostructured thin films could lead to the design of new kinds of membranes with a variable mechanical response for a wide range of applications.
The days of self-assembling nanoparticles taking hours to form a film over a microscopic-sized wafer are over. Researchers with Lawrence Berkeley National Laboratory have devised a technique whereby self-assembling nanoparticle arrays can form a highly ordered thin film over macroscopic distances in one minute.
Essential oils have boomed in popularity as people seek alternatives to replace their synthetic cleaning products, anti-mosquito sprays and medicines. Now scientists are tapping them as candidates to preserve food in a more consumer-friendly way. A study from the Journal of Agricultural and Food Chemistry reports the development of new edible films containing oils from clove and oregano that preserve bread longer than commercial additives.
In the wake of recent offshore oil spills, and with the growing popularity of “fracking”—in which water is used to release oil and gas from shale—there’s a need for easy, quick ways to separate oil and water. Now, scientists have developed coatings that can do just that. Their report on the materials, which also could stop surfaces from getting foggy and dirty, appears in ACS Applied Materials & Interfaces.
Saudi Arabian-based petrochemical company SABIC and Cima NanoTech have announced the joint development of a new transparent conductive polycarbonate film. The collaboration leverages both Cima NanoTech’s proprietary SANTE nanoparticle technology and SABIC’s LEXAN film to produce a film that outperforms indium tin oxide by a factor of ten.
Researchers in Spain have introduced a platform technology based on optical antennas for trapping and controlling light with graphene. Their experiments show that the dramatically squeezed graphene-guided light can be focused and bent, following the fundamental principles of conventional optics. The work opens new opportunities for smaller and faster photonic devices and circuits.
Scientists at the Korea Advanced Institute of Science and Technology have increased the energy efficiency of a piezoelectric nanogenerator by almost 40 times, moving it closer to commercial flexible energy harvesters that can supply power infinitely to wearable, implantable electronic devices. The technique used to make this improvement, laser lift-off, allows the placement of a high-quality piezoelectric film on a sapphire substrate.
A research team that figured out how to coat an organic material as a thin film wanted a closer look at why their spreadable organic semiconductor grew like it did. So Cornell Univ. scientists used their high-energy synchrotron x-ray source to show how these organic molecules formed crystal lattices at the nanoscale. These high-speed movies could help advance the technology move from the laboratory to mass production.
Vanadium dioxide is called a "wacky oxide" because it transitions between a conducting metal and an insulating semiconductor and with the addition of heat or electrical current. A device created by Penn State engineers uses a thin film of vanadium oxide on a titanium dioxide substrate to create an oscillating switch that could form the basis of a computational device that uses a fraction of the energy necessary for today’s computers.
Optical metamaterials harness clouds of electrons called surface plasmons to manipulate and control light. However, plasmonic devices often use gold or silver, which is incompatible with CMOS manufacturing processes. Purdue Univ. scientists have now developed an ultra-thin crystalline superlattice that instead uses metal-dielectrics. Applied using epitaxy, this “hyperbolic” film could greatly expand applications for metamaterials.
While flexible gadgets such as “electronic skin” and roll-up touch screens are moving ever closer to reality, their would-be power sources are either too wimpy or too stiff. But that’s changing fast. Scientists have developed a new device that’s far thinner than paper, can flex and bend, and store enough energy to provide critical back-up power for portable electronics.
Current approaches to flexible electronics, in which very thin semiconductor materials are applied to a thin, flexible substrate in wavy patterns and then applied to a deformable surface such as skin or fabric, are still built around hard composite materials that limit their elasticity. Researchers in California have made several discoveries, however, that could lead to electronics that are "molecularly stretchable."
Researchers in Spain have developed a highly fluorescent hybrid material that changes color depending on the polarization of the light that it is illuminated by. They achieved this with a perfect fit between an inorganic nanostructure and dye molecules.
Transparent conductive (TCO) films, present in tablets, laptops, flat screens and solar cells, are now an integral part of our lives. Yet they are expensive and complex to manufacture. Researchers in Europe have recently succeeded in developing a method of producing TCO films that relies on molecular self-organization. The technique is cheaper, simpler and more environmentally friendly than the traditional sputtering approach.
Treating cadmium-telluride (CdTe) solar cell materials with cadmium-chloride improves their efficiency, but researchers have not fully understood why. Now, an atomic-scale examination of the thin-film solar cells led by Oak Ridge National Laboratory has answered this decades-long debate about the materials’ photovoltaic efficiency increase after treatment.
Solar Frontier and the State Univ. of New York College of Nanoscale Science and Engineering have signed a memorandum of understanding to conduct a technical and economic feasibility study for potential joint R&D and manufacturing of CIS thin-film modules in Buffalo, New York. This move is part of Solar Frontier’s plans to establish production bases for its proprietary technology outside of Japan, the company’s home market.
A bullet fired through a block of wood will slow down. In a similar way, ions are decelerated when they pass through a solid material: the thicker the material, the larger the energy loss will be. However, as recent experiments in Austria have shown, this picture breaks down in ultra-thin target materials, which only consist of a few layers of atoms.
Of late, engineers have been paying more and more attention to nature’s efficiencies, such as the Lotus effect, which describes the way the Lotus plant uses hydrophobic surfaces to survive in muddy swamps. A researcher at Virginia Tech has developed a simpler two-step application process to create a superhydrophobic copper surface that leverages the Lotus effect.
Researchers have produced a stable porous membrane that is thinner than a single nanometer. The membrane consists of two layers of graphene on which have been etched tiny pores of a precisely defined size. Extremely light and breathable, the new material could help enable a new generation of ultra-rapid filters or functional waterproof clothing.
Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides. Researchers from Cornell Univ. and Brookhaven National Laboratory have shown how to switch a particular transition metal oxide, a lanthanum nickelate (LaNiO3), from a metal to an insulator by making the material less than a nanometer thick.