Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by simply changing their dimensions. New research at Los Alamos National Laboratory aims to improve quantum dot-based light-emitting diodes by using a new generation of engineered quantum dots tailored specifically to have reduced wasteful charge-carrier interactions that compete with the production of light.
The direct emission of terahertz radiation would be useful in science, but no laser has yet been developed which can provide it. A team headed of researchers have now demonstrated that graphene meets an important condition for use in novel lasers for terahertz pulses with long wavelengths: It permits population inversion, a key prerequisite for stimulated radiation emission.
By tuning gold nanoparticles to just the right size, researchers from Brown Univ. have developed a catalyst that selectively converts carbon dioxide to carbon monoxide, an active carbon molecule that can be used to make alternative fuels and commodity chemicals.
Semiconductor Research Corporation (SRC) has launched a new research program on hybrid bio-semiconductor systems that they hope will provide insights and opportunities for future information and communication technologies. The Semiconductor Synthetic Biology (SSB) program will initially fund research at six universities.
Amy Prieto, a chemist at Colorado State Univ. leads a start-up company with the goal of developing a lithium-ion battery that should be safer, cheaper, faster-charging, and more environmentally friendly than conventional batteries now on the market. The key to the technology is copper foam which is easy to manufacture and has high power density.
Of all the standard units currently in use around the world, the kilogram is the only one that still relies on a physical object for its definition. But revising this outdated definition will require precise vacuum-based measurements that researchers are not yet able to make. A new system is in development that would allow a direct comparison of an object being weighed in a vacuum to one outside a vacuum.
As microelectronics get smaller and smaller, one of the biggest challenges to packing a smartphone or tablet with maximum processing power and memory is the amount of heat generated by the tiny “switches” at the heart of the device. A complex metal-oxide film could help reduce the voltage required to switch electronic signals, and thus the excessive energy they require.
Scientists have used the powerful x-ray laser at the SLAC National Accelerator Laboratory to create movies detailing trillionths-of-a-second changes in the arrangement of copper atoms after an extreme shock. The study pinpointed the precise breaking point when the extreme pressures began to permanently deform the copper structure, or lattice, so it could no longer bounce back to its original shape.
A new study set out to use numerical simulations to validate previous theoretical predictions describing materials exhibiting so-called antiferromagneting characteristics. A recently discovered theory shows that the ordering temperature depends on two factors—namely the spin-wave velocity and the staggered magnetization. The simulations match these theoretical predictions.
Researchers at Purdue Univ. are developing a method to mass-produce a new type of nanomaterial for advanced sensors and batteries, with an eye toward manufacturing in the Midwest. Research findings indicate the material shows promise as a sensor for detecting glucose in the saliva or tears and for "supercapacitors" that could make possible fast-charging, high-performance batteries.
Active camouflage has taken a step forward at Harvard Univ., with a new coating that intrinsically conceals its own temperature to thermal cameras. In a laboratory test, a team placed the device on a hot plate and watched it through an infrared camera as the temperature rose. Initially, it behaved as expected, giving off more infrared light as the sample was heated.
As electronics approach the atomic scale, researchers are increasingly successful at developing atomically thin, virtually 2-D materials that could usher in the next generation of computing. Integrating these materials to create necessary circuits, however, has remained a challenge. Northwestern Univ. researchers have now taken a significant step toward fabricating complex nanoscale electronics.
Researchers have recently provided the first evidence ever that it is possible to generate a magnetic field by using heat instead of electricity. The phenomenon is referred to as the Magnetic Seebeck effect or “thermomagnetism”.
When it comes to designing extremely water-repellent surfaces, shape and size matter. That's the finding of a group of scientists at Brookhaven National Laboratory, who investigated the effects of differently shaped, nanoscale textures on a material's ability to force water droplets to roll off without wetting its surface.
Scientists at Brookhaven National Laboratory have developed a general approach for combining different types of nanoparticles to produce large-scale composite materials. The technique opens many opportunities for mixing and matching particles with different magnetic, optical or chemical properties to form new, multifunctional materials or materials with enhanced performance for a wide range of potential applications.
A South Korean joint industrial-academic research team has developed the technology to put forward the commercialization of nanowire that is only a few nanometers wide. In cooperation with LG Innotek and the National Nanofab Center, Prof. Jun-Bo Yoon, from KAIST Dept. of Electrical Engineering, developed the technology to mass produce nanowire at any length with various materials.
Materials in lithium ion battery electrodes expand and contract during charge and discharge. These volume changes drive particle fracture, which shortens battery lifetime. A group of scientists has quantified this effect for the first time using high-resolution 3D movies recorded using x-ray tomography at the Swiss Light Source.
Although the amount of data that can be stored has increased immensely during the past few decades, it is still difficult to actually store data for a long period of time. A researcher has recently demonstrated a way to store data for extremely long periods, even millions of years, using an etched wafer made of tungsten encapsulated by silicon nitride. The material is resistant to both time and elevated temperatures.
Vanadium dioxide is one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures starting around 67 C. This temperature-driven metal-insulator transition, the origin of which is still intensely debated, could be induced by the application of an external electric field. Beamline studies at the Advanced Light Source has shed some light on this potential avenue for faster electronics.
Earth’s most eminent emissary to Mars has just proven that those rare Martian visitors that sometimes drop in on Earth really are from the Red Planet. A key new measurement of Mars’ atmosphere by NASA’s Curiosity rover provides the most definitive evidence yet of the origins of Mars meteorites while at the same time providing a way to rule out Martian origins of other meteorites.
Scientists have created a heat-resistant thermal emitter that could significantly improve the efficiency of solar cells. The novel component is designed to convert heat from the sun into infrared light, which can then be absorbed by solar cells to make electricity. Unlike earlier prototypes that fell apart at temperatures below 1,200 C, the new thermal emitter remains stable at temperatures as high as 1,400 C.
Scientists at Rice Univ. are enhancing the natural antioxidant properties of an element found in a car’s catalytic converter to make it useful for medical applications. The team created small, uniform spheres of cerium oxide and gave them a thin coating of fatty oleic acid to make them biocompatible.
Rubber can be extracted from the juice of the dandelion, but transitioning this technology to the industrial setting has been a challenge. The Fraunhofer Institute in Germany has joined with Continental tire company to build the first-ever pilot system to extract vast quantities of dandelion rubber for making tires
Researchers at Johns Hopkins Univ. have succeeded in making flattened, football-shaped artificial particles that impersonate immune cells. These football-shaped particles seem to be better than the typical basketball-shaped particles at teaching immune cells to recognize and destroy cancer cells in mice.
Any medical device implanted in the body attracts bacteria to its surface, causing infections and thrombosis that lead to many deaths annually. Devices can be coated with antibiotics and blood thinners, but these eventually dissolve, limiting their longevity and effectiveness. Now, Semprus BioSciences is developing a novel biomaterial for implanted medical devices that barricades these troublesome microbes from the device’s surface.