Researchers at Pacific Northwest National Laboratory have developed a porous material to replace the graphite traditionally used in a battery's electrodes. Made from silicon, which has more than 10 times the energy storage capacity of graphite, the sponge-like material can help lithium-ion batteries store more energy and run longer on a single charge.
An international research collaboration has designed a miniscule cooling element that uses spin waves to transport heat in electrical insulators. Although physicists have used spin for cooling purposes before, this is the first time that they have successfully done this in insulating materials. The cooling element could be used to dissipate heat in the increasingly smaller electrical components of computer chips.
For the last century, the concept of crystals has been a mainstay of solid-state physics. Crystals are paragons of order; crystalline materials are defined by the repeating patterns their constituent atoms and molecules make. Now physicists have evidence that a new concept should undergird our understanding of most materials: the anticrystal, a theoretical solid that is completely disordered.
Robert Wolkow and his team at the Univ. of Alberta are working to engineer atomically precise computing technologies that have practical, real-world applications. In recent research, he and his team observed for the first time how an electrical current flows across the skin of a silicon crystal and also measured electrical resistance as the current moved over a single atomic step.
Iron is present in tiny concentrations in seawater, on the order of a few billionths of a gram in a liter. However, its availability in seawater can have a profound effect on phytoplankton growth and, consequently, the Earth's carbon cycle. In recent research, an assessment was made of the various sources of dissolved iron in the north Atlantic Ocean and surprising discoveries were made about their origins.
Using graphene ribbons just several atoms across, a group of researchers at the Univ. of Wisconsin-Milwaukee has found a novel way to “tune” the material, causing the extremely efficient conductor of electricity to act as a semiconductor. By imaging the ribbons with scanning-tunneling microscopy, researchers have confirmed how narrow the ribbon width must be. Achieving less than 10 nm in width is a big challenge.
Located deep in the human gut, the small intestine is not easy to examine: X-rays, MRIs and ultrasound images each suffer limitations. Univ. at Buffalo researchers are developing a new imaging technique involving nanoparticles suspended in liquid to form “nanojuice” that patients would drink. Upon reaching the small intestine, doctors would strike the nanoparticles with laser light, providing a non-invasive, real-time view of the organ.
Nonlinear optical materials are widely used in laser systems, but they require high light intensity and long propagation to be effective. A team in Germany and Texas has designed a new 400-nm thick nonlinear mirror that delivers frequency-doubled output using input light intensity as small as that of a laser pointer. Compared to traditional nonlinear materials, the new option offers a million times increase in nonlinear optical response.
Ancient Japanese gold leaf artists were truly masters of their craft. An analysis of six of these Japanese paper screens show that these artifacts are gilded with gold leaf that was hand-beaten to the nanometer scale. The study was able to prove this without any damage to the screens through the use of x-ray fluorescence spectroscopy.
Using something called a microchannel heat sink to simulate the warm environment of a working computer, researchers in Malaysia have analyzed three nanofluids for the traits that are important in an effective coolant. The results of their study show that the nanofluids, which are made of metallic nanoparticles that have been added to a liquid, such as water, all performed better than water as coolants, with one mixture standing out.
Known as the “world's longest experiment”, an experiment at the University of Queensland in Australia was famous for taking ten years for a drop of pitch, a black, sticky material, to fall from a funnel. A new test in the U.K. is using a different bitumen, or pitch, which is 30 times less viscous than the Queensland experiment, so that the flow can be seen at a faster rate and hopefully provide more insights.
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.
Experts don't fully understand how “plastic” solar panels work, which complicates the improvement of their cost efficiency and hinders wider use of the technology. However, an international team has now determined how light beams excite the chemicals in solar panels, enabling them to produce charge. Their findings were made possible with the use of femtosecond Raman spectroscopy.
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.
Plastic junk is floating widely on the world's oceans, but there's less of it than expected, a study says. A newly published study drew on results from an around-the-world cruise by a research ship that towed a mesh net at 141 sites, as well as other studies. Researchers estimated the total amount of floating plastic debris in open ocean at 7,000 to 35,000 tons.
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.
Experiments aimed at devising new types of photodetectors have been triggered by the increasing use of optoelectronic devices. Researchers in China have proposed a new type of infrared photodetector made from zinc oxide and silicon. Its nanoporous nature, synthesized by a simple sol-gel method, allows it to be responsive to infrared wavelengths.
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.
Computer simulation has shown Stanford Univ. engineers how to make a crystal that would toggle like a light switch between conductive and non-conductive structures. This flexible, switchable lattice, just three atoms thick, can be turned on or off by mechanically pushing or pulling, and could lead to flexible electronic materials.
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.
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.
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.