Materials developers have had high hopes for using carbon nanotubes to desalinate seawater. However, a simulation recently conducted in Europe reveals that the ultra-fast transport rates required to accomplish this task have not been correctly measured in carbon nanotubes. These new findings suggest the use of a carbon nanotube membranes as a filter medium rather a transport mechanism might be more realistic.
A University of British Columbia engineer and a team of U.S. researchers have made a breakthrough utilizing spray-on technology that could revolutionize the way optical lenses are made and used. Nearly all lenses—whether in an eye, a camera, or a microscope—are presently curved, which limits the aperture, or amount of light that enters. The new spray-on lens is flat, and can be affixed to a glass slide.
Researchers at North Carolina State University have developed a new technique for creating high-quality semiconductor thin films at the atomic scale—meaning the films are only one atom thick. The technique can be used to create these thin films on a large scale, sufficient to coat wafers that are two inches wide, or larger.
Inspired by the structure of moth eyes, researchers at North Carolina State University have developed nanostructures that limit reflection at the interfaces where two thin films meet, suppressing the “thin-film interference” phenomenon commonly observed in nature. This can potentially improve the efficiency of thin-film solar cells and other optoelectronic devices.
Thin films sometimes grow layer by layer, each layer one atom thick, while in other cases atoms deposited onto a surface form 3D islands that grow, impinge, and coalesce into a continuous film. Scientists have traditionally assumed that the islands are homogeneous and coalesce at roughly the same time. In a recent study, researchers have discovered that the process is more dynamic than suggested by the traditional view.
An international team working to image ferroelectric thin films have reported the development of a new X-ray imaging technique, coherent X-ray Bragg projection ptychography. Under certain conditions, these thin films, which are used in computer memory, form networks of nanoscale domains with distinct local polarizations that are normally difficult to image.
Magnetic vortices typically occur in nanometer-scale magnetic disks, which are studied for their potential roles in wireless data transmission. So far, magnetic vortex states have been observed only within a plane, but recently researchers in Europe have discovered 3D magnetic vortices for the first time in a specially designed stack of magnetic disks.
A polymer thin film solar cell (PSC) produces electricity from sunlight by the photovoltaic effect. Though light and inexpensive, PSCs currently suffer from a lack of enough efficiency for large scale applications and they also have stability problems. Researches in Korea have designed and added multi-positional silica-coated silver nanoparticles that have greatly improved stability and performance of these cells.
Like spreading a thin layer of butter on toast, Cornell University scientists have helped develop a novel process of spreading extremely thin organic transistors, and used synchrotron X-rays to watch how the films crystallize. The coating procedure, called solution shearing, is like the buttering of a slice of toast.
Ditch the 3D glasses. Thanks to a simple plastic filter, mobile device users can now view unprecedented, distortion-free, brilliant 3D content with the naked eye. This latest innovation from researchers in Singapore is the first ever glasses-free 3D accessory that can display content in both portrait and landscape mode, and measures less than 0.1 mm in thickness.
There is high interest in methods to produce 2D crystals by exfoliating materials with layered structures, but certain ions or solvents can infiltrate materials with layered structures, forcing exfoliation spontaneously and complicating efforts to build practical materials. While working to develop these procedures, researchers in Japan have reported an unusual phenomenon that layered materials undergo drastic swelling without breaking into separate 2D crystal layers.
Scientists at the U.S. Naval Research Laboratory have fabricated a vapor sensor using a single monolayer of molybdenum disulfide (MoS2) on a silicon dioxide wafer. They show that it functions effectively as a chemical vapor sensor, exhibiting highly selective reactivity to a range of analytes, and providing sensitive transduction of transient surface physisorption events to the conductance of the monolayer channel.
Imagine if you could drink a glass of water just by inserting a solid wire into it and sucking on it as though it were a soda straw. It turns out that if you were tiny enough, that method would work just fine—and wouldn’t even require the suction to start. New research has demonstrated, for the first time, that when inserted into a pool of liquid, nanowires naturally draw the liquid upward in a thin film that coats the surface of the wire.
According to recent research at Rice University, vanadium oxide and graphene may be a key new set of materials for improving lithium-ion storage. Ribbons created at Rice from these two materials are thousands of times thinner than a sheet of paper, yet have potential that far outweighs current materials for their ability to charge and discharge very quickly. Initial capacity remains at 90% or more after more than 1,000 cycles.
Semiconducting polymers are an unruly bunch, but University of Michigan engineers have developed a new method for getting them in line that could pave the way for cheaper, greener, "paint-on" plastic electronics.
A current optical-sensing technology can launch and guide a single light wave, called a surface-plasmon-polariton (SPP) wave, that travels along the flat interface of the sample to be analyzed. However, only one wave can be used, allowing the analysis of just one substance. Researchers at Penn State University have designed a thin film that can create additional channels for the SPP waves.
For years, researchers have developed thin films of bismuth telluride, which converts heat into electricity or electricity to cooling, on top of gallium arsenide to create cooling devices for electronics. But it was not clear how this could be done because the atomic structures do not appear to be compatible. Researchers from North Carolina State University and RTI International have now solved the mystery.
A multi-university research team has used a new spectroscopic method—energy-momentum spectroscopy—to gain a key insight into how light is emitted from layered nanomaterials and other thin films. The technique lets researchers understand the source and orientation of light in light-emitting thin films and could lead to better LEDs, solar cells, and other devices that use layered nanomaterials.
Until recently, there has been no systematic way of evaluating how different anti-fog coatings perform under real-world conditions. A team of MIT researchers has developed such a testing method, and used it to find a coating that outperforms others not only in preventing foggy buildups, but also in maintaining good optical properties without distortion.
The salinity difference between freshwater and saltwater could be a source of renewable energy. However, power yields from existing techniques are not high enough to make them viable. A team led by physicists in France has discovered a new means of harnessing this energy. Their method of osmotic flow through boron nitride nanotubes generates electric currents with 1,000 times the efficiency of any previous system.
Northwestern University’s Yonggang Huang and the University of Illinois’ John A. Rogers are the first to demonstrate a stretchable lithium-ion battery—a flexible device capable of powering their innovative stretchable electronics. Their battery continues to work—powering a commercial light-emitting diode (LED)—even when stretched, folded, twisted and mounted on a human elbow. The battery can work for eight to nine hours before it needs recharging, which can be done wirelessly.
New research by Yale University scientists helps pave the way for the next generation of solar cells, a renewable energy technology that directly converts solar energy into electricity. In a pair of recent papers, Yale engineers report a novel and cost-effective way to improve the efficiency of crystalline silicon solar cells through the application of thin, smooth carbon nanotube films.
Recent research shows that a newly discovered class of materials, called layered oxide heterostructures, could have optimal electrical characteristics. A research team at the Vienna University of Technology, together with colleagues from the United States and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells.
Like turning coal to diamond, adding pressure to an electrical material enhances its properties. Now, University of Illinois at Urbana-Champaign researchers have devised a method of making ferroelectric thin films with twice the strain, resulting in exceptional performance.
Researchers have tried for decades to replicate the effects of transistors in transition metal oxides by using a voltage to convert the material from an insulator to a metal, but the induced change only occurs within a few atomic layers of the surface. Recently, however, scientists in Japan have discovered that applying a voltage to a vanadium dioxide film several tens of nanometers thick converts the entire film from an insulator to a metal.