[Image above] Credit: NIST
NANOMATERIALS
Ultrathin, flat lens resolves chirality and color
Researchers at Harvard John A. Paulson School of Engineering and Applied Sciences have developed an ultra-compact, flat lens that can simultaneously capture both spectral information and the chirality of an object. The lens consists of two arrays of titanium oxide nanofins on one glass substrate, which forms two images of opposite chirality.
Researchers discover new way to turn electricity into light, using graphene
When an airplane begins to move faster than the speed of sound, it creates a shockwave that produces a well-known “boom” of sound. Now, researchers at MIT and elsewhere have discovered a similar process in a sheet of graphene, in which a flow of electric current can, under certain circumstances, exceed the speed of slowed-down light and produce a kind of optical “boom”: an intense, focused beam of light.
New technique determines chemical composition of materials using light
Researchers from the University of Houston have reported a new technique to determine the chemical composition of materials using near-infrared light. The team tuned nanoporous gold disks to react when exposed to specific wavelengths, making it possible to develop a sensing technique with the advantages of both infrared and near infrared scanning.
ENERGY
‘Flower power’: Photovoltaic cells replicate rose petals
With a surface resembling that of plants, solar cells improve light-harvesting and thus generate more power. Scientists reproduced the epidermal cells of rose petals that have particularly good antireflection properties and integrated the transparent replicas into an organic solar cell. This resulted in a relative efficiency gain of 12%.
Better way to ‘herd’ electrons in solar fuel devices
Researchers at the University of British Columbia and the University of North Carolina at Chapel Hill have discovered a new way to optimize electron transfer in semiconductors used in solar fuel solutions. The new finding shows that the efficiency of the transfer also depends on the type of chemical bonds that the electron travels through along the way.
Chemists find new way to recycle plastic waste into fuel
A new way of recycling millions of tons of plastic garbage into liquid fuel has been devised by researchers from the University of California, Irvine and the Shanghai Institute of Organic Chemistry in China. The team figured out how to break down the strong bonds of polyethylene. Their innovative technique centers on the use of alkanes, specific types of hydrocarbon molecules, to scramble and separate polymer molecules into other useful compounds.
Loofah-based material could give lithium batteries a boost
Today’s mobile lifestyle depends on rechargeable lithium batteries. But to take these storage devices to the next level—to shore up the electric grid or for widespread use in vehicles, for example—they need a big boost in capacity. To get lithium batteries up to snuff for more ambitious applications, researchers report a new solution that involves low-cost, renewable loofah sponges.
Researchers find new ways to make clean hydrogen, rechargable zinc batteries
A Stanford University research lab has developed new technologies to tackle two of the world’s biggest energy challenges—clean fuel for transportation and grid-scale energy storage. The team developed a novel material for photovoltaic water splitting and also designed a novel battery with electrodes made of zinc and nickel, inexpensive metals with the potential for grid-scale storage.
ENVIRONMENT
NASA scientists discover unexpected mineral on Mars
Scientists have discovered an unexpected mineral in a rock sample at Gale Crater on Mars, a finding that may alter our understanding of how the planet evolved. Curiosity, has been exploring sedimentary rocks within Gale Crater since landing in August 2012. Analyzing data from an X-ray diffraction instrument on the rover that identifies minerals, scientists detected significant amounts of a silica mineral called tridymite.
New surface makes oil contamination remove itself
Researchers of Aalto University have developed surfaces where oil transports itself to desired directions. Researchers’ oleophobic surfaces are microtextured with radial arrays of undercut stripes. When oil drops fall on surfaces, drops move away from the landing point to the direction set by asymmetric geometrical patterning of the surface.
Ultra-thin slices of diamonds reveal geological processes
By using ultra-thin slices of diamonds, researchers have found the first direct evidence for the formation of diamonds by a process known as redox freezing. In this process, carbonate melts crystallize to form diamond. The study shows that the reduction of carbonate to diamond is balanced by the oxidation of iron sulphide to iron oxides.
OTHER RESEARCH
Neutrons reveal unexpected magnetism in rare-earth alloy
A new study by a multi-institutional team, led by researchers from Brookhaven National Laboratory and Stony Brook University, has revealed exotic magnetic properties in a rare-earth based intermetallic compound, ytterbium-platinum-lead (Yb2Pt2Pb). Surprisingly, this 3-D material exhibits magnetic properties that one would conventionally expect if the connectivity between magnetic ions was only 1-D.
New see-through material for electronics
Creating more efficient lighting solutions and solar panels requires materials that let light pass through and conduct “missing electrons.” Scientists created just such a material by altering a transparent insulating oxide by chemical substitution. Even though conducting missing electrons and transparency were considered mutually exclusive, this new material both efficiently conducts missing electrons and retains most of its transparency to visual light.
Finding a needle in a crystalline haystack
Revealing new insights into how materials become “fatigued” and fail, a new X-ray analysis technique clearly shows the culprit—rare, abnormally large crystalline regions. With this new technique, scientists can detect a few large grains in a sea of small grains and study the fatigue-induced phenomena of large grain growth.
Map of diamond-boron bond paves way for new materials
Scientists in Japan have successfully recorded the atomic bonds between diamond and cubic boron nitride: the hardest known materials on earth. This feat could ultimately lead to the design of new types of semiconductors. The team imaged bonded diamond and boron nitride using a super-high-resolution scanning electron microscope, and then subjected those observations to extensive theoretical calculations.
Atomic sculpting with a microscope
A new tool now rests in the 3-D printing toolbox. The electron beam in a scanning transmission electron microscope has been exquisitely controlled with specially programmed electronics to tunnel into non-crystalline material and construct 3-D features that are in perfect alignment with the underlying substrate. The result is designer materials with desirable structures, such as microchips, or materials with unique properties.