Research led by Penn State Univ. and Cornell Univ. physicists is studying "spintorque" in devices that combine a standard magnetic material with a new material known as a topological insulator. The new insulator, which is made of bismuth selenide and operates at room temperature, overcomes one of the key challenges to developing a spintronics technology based on spin-orbit coupling.
Researchers have discovered a previously unknown mechanism for wear in metals: a swirling, fluid-like microscopic behavior in a solid piece of metal sliding over another. The findings could be used to improve the durability of metal parts in numerous applications.
More than a decade ago, news of a Namibian desert beetle’s efficient water collection system inspired engineers to try and reproduce these surfaces in the laboratory. Small-scale advances in fluid physics, materials engineering and nanoscience since that time have brought them close to succeeding. And their work could have impact on a wide range of industries at the macroscale.
Highly purified crystals that split light with precision are valued in specialized optics. But photonic crystals are difficult to make with current techniques, namely electron beam etching. Researchers at Princeton and Columbia universities have proposed a new method derived from colloidal suspensions that could allow scientists to customize and grow optimal crystals with relative ease.
By “drawing” micropatterns on nanomaterials using a focused laser beam, scientists in Singapore have modifed properties of nanomaterials for effective photonic and optoelectronic applications. Their method increased electrical conductivity and photoconductivity of the modified molybdenum disulfide material by more than 10 times and about five times respectively.
Researchers in Spain have announced their successful effort to build a silicon 1-D optomechanical crystal so that it allows both phonons and photons to localize in a stable way. This marks an opportunity to study the interaction between electromagnetic radiation and mechanical vibrations of matter with a new level of precision.
By colliding ultra-small gold particles with a surface and analyzing the resulting fragments, a trio of scientists at Pacific Northwest National Laboratory discovered how and why the particles break. This information is important for controlling the synthesis of these tiny building blocks that are of interest to catalysis, energy conversion and storage, and chemical sensing.
Vibrate a solution of rod-shaped metal nanoparticles in water with ultrasound and they'll spin around their long axes like tiny drill bits. Why? No one yet knows exactly. But researchers at the NIST have clocked their speed, and it's fast. At up to 150,000 revolutions per minute, these nanomotors rotate 10 times faster than any nanoscale object submerged in liquid ever reported.
Graphene, a material that consists of a lattice of carbon atoms, one atom thick, is widely touted as being the most electrically conductive material ever studied. However, not all graphene is the same. With so few atoms comprising the entirety of the material, the arrangement of each one has an impact on its overall function.
The yield so far is small, but chemists at the Univ. of Oregon have developed a low-energy, solution-based mineral substitution process to make a precursor to transparent thin films. The inorganic process is a new approach to transmetalation, in which individual atoms of one metal complex are individually substituted in water. The innovation could find use in electronics and alternative energy devices.
Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice Univ. scientists. Stretching the material known as carbyne by just 3% can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.
A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells. A new study from Massachusetts Institute of Technology materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons.
Scientists have successfully tested a material that can extract atoms of rare or dangerous elements such as radon from the air. Gases such as radon, xenon and krypton all occur naturally in the air but in minute quantities—typically less than one part per million. As a result they are expensive to extract for use in industries such as lighting or medicine and, in the case of radon, the gas can accumulate in buildings.
A new material structure developed at Massachusetts Institute of Technology generates steam by soaking up the sun. The structure—a layer of graphite flakes and an underlying carbon foam—is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam.
A Univ. of Alabama start-up company, 525 Solutions, has received about $1.5 million from the federal government to refine an invention to extract uranium from the ocean for use as fuel. It is an adsorbent, biodegradable material made from the compound chitin, which is found in crustaceans and insects. The researchers have developed transparent sheets, or mats, comprised of tiny chitin fibers, which pull uranium from the water.
One of the major road blocks to the design and development of new, more efficient solar cells may have been cleared. Researchers with the Lawrence Berkeley National Laboratory have developed the first ab initio method for characterizing the properties of “hot carriers” in semiconductors. Hot carriers are electrical charge carriers with significantly higher energy than charge carriers at thermal equilibrium.
Nearly all electronics require devices called oscillators that create precise frequencies. For nearly 100 years, these oscillators have relied upon quartz crystals to provide a frequency reference, much like a tuning fork is used as a reference to tune a piano. However, future high-end navigation systems, radar systems and even possibly tomorrow's consumer electronics will require references beyond the performance of quartz.
Researchers at the Univ. of Illinois at Urbana-Champaign have demonstrated that an array of novel gold, pillar-bowtie nanoantennas (pBNAs) can be used like traditional photographic film to record light for distances that are much smaller than the wavelength of light (for example, distances less than ~600 nm for red light). A standard optical microscope acts as a “nanocamera” whereas the pBNAs are the analogous film.
Researchers have taken a major stride toward perfectly efficient lighting that is also relatively inexpensive and simple to make. The same material can also reveal the presence of water by changing color. Incandescent bulbs only turn 5% of the electricity they use into light, while fluorescent LEDs can produce light from up to 25% of the electrons that pass through them. Phosphorescent LEDs can turn every electron into a ray of light.
The common pencil squid may hold the key to a new generation of medical technologies that could communicate more directly with the human body. Materials science researchers in California have discovered that reflectin, a protein in the tentacled creature’s skin, can conduct positive electrical charges, or protons, making it a promising material for building biologically inspired devices.
A team including scientists from Spain and from IBM Research in Switzerland have published work which describes an extremely simple method to obtain high quality nanographenes from easily available organic compounds. This method is based on the reactivity of a group of molecules named arynes, which can act as "molecular glue" to paste graphene fragments together.
Scientists in Texas have created a unique sensor that amplifies the optical signature of molecules by about 100 billion times. The new imaging method uses a form of Raman spectroscopy in combination with an intricate but mass reproducible optical amplifier. Newly published tests found the device could accurately identify the composition and structure of individual molecules containing fewer than 20 atoms.
New York state is teaming with General Electric Co. and other companies on a $500 million initiative to spur high-tech manufacturing of miniature electronics, Gov. Andrew Cuomo and GE CEO Jeffrey Immelt announced Tuesday. The state will invest $135 million for the collaborative program, which will be based out of the SUNY College of Nanoscale Science and Engineering in Albany.
A 3-D porous nanostructure would have a balance of strength, toughness and ability to transfer heat that could benefit, nanoelectronics, gas storage and composite materials that perform multiple functions, according to engineers at Rice Univ. The researchers made this prediction by using computer simulations to create a series of 3-D prototypes with boron nitride, a chemical compound made of boron and nitrogen atoms.
Together with teams from Finland and Japan, physicists from the Univ. of Basel in Switzerland were able to place 20 single bromine atoms on a fully insulated surface at room temperature to form the smallest “Swiss cross” ever created. The effort is a breakthrough because the fabrication of artificial structures on an insulator at room temperature is difficult. It is largest number of atomic manipulations ever achieved at room temperature.