Material Science
Manipulating ultrafast spin at terahertz frequencies
April 3, 2013 10:46 am | News | CommentsThe use of femtosecond light pulses—the fastest man-made event—with photon energies ranging from X-rays (as used for instance at the HZB femto-slicing facility) to terahertz spectral range has proved to be an indispensable tool in ultrafast spin and magnetization dynamics studies. Researchers have recently demonstrated a simple but powerful way of manipulating the spins at these unprecedented speeds.
A new way to create synthetic polymers using genetic coding in DNA
April 2, 2013 7:45 am | by Peter Reuell, Harvard University | News | CommentsScientists may soon be able to turn to one of the most powerful forces in biology—evolution—to help in their quest to develop new synthetic polymers. As described in a recent paper, a team of Harvard University researchers has developed a new method to create synthetic polymers using the coding of genetic material. The method may eventually be used to evolve synthetic polymers with new or improved properties such as the ability to serve as catalysts in chemical reactions or enhanced therapeutic potential.
Inorganic materials display massive swelling and shrinkage
April 1, 2013 8:15 pm | News | CommentsThere 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.
Watching fluid flow at nanometer scales
April 1, 2013 7:34 am | by David L. Chandler, MIT News Office | News | CommentsImagine 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.
Even graphene has weak spots
March 29, 2013 7:51 am | News | CommentsGraphene has become famous for its extraordinary strength. But less-than-perfect sheets of the material show unexpected weakness, according to researchers at Rice University and Tsinghua University. The kryptonite to this Superman of materials is in the form of a seven-atom ring that inevitably occurs at the junctions of grain boundaries in graphene, where the regular array of hexagonal units is interrupted. At these points, under tension, polycrystalline graphene has about half the strength of pristine samples of the material.
Nanoscale edge variations observed with record-breaking resolution
March 28, 2013 9:35 am | News | CommentsA team of researchers from the Royal Institute of Technology, Stockholm, the University of Maryland, and NIST have measured large variations in the magnetic properties along the edge of a thin-film 500-nm-diameter disk. This work represents a significant development in the measurement of magnetic thin-film edge properties, which are especially important for nanodevices, such as magnetic memory cells, where the edge to area ratio is large.
Engineers develop nanofoams for better body armor
March 26, 2013 10:50 am | News | CommentsEngineers at the University of California, San Diego are developing nanofoams that could be used to make better body armor; prevent traumatic brain injury and blast-related lung injuries in soldiers; and protect buildings from impacts and blasts. It’s the first time researchers are investigating the use of nanofoams for structural protection.
Metascreen forms ultrathin invisibility cloak
March 26, 2013 8:35 am | News | CommentsUp until now, the invisibility cloaks put forward by scientists have been fairly bulky contraptions—an obvious flaw for those interested in Harry Potter-style applications. However, researchers from the U.S. have now developed a cloak that is just micrometers thick and can hide 3D objects from microwaves in their natural environment, in all directions and from all of the observers’ positions.
Trees used to create recyclable, efficient solar cell
March 26, 2013 8:01 am | News | CommentsSolar cells are just like leaves, capturing the sunlight and turning it into energy. It’s fitting that they can now be made partially from trees. Georgia Institute of Technology and Purdue University researchers have developed efficient solar cells using natural substrates derived from plants such as trees. Just as importantly, by fabricating them on cellulose nanocrystal substrates, the solar cells can be quickly recycled in water at the end of their lifecycle.
Hybrid ribbons a gift for powerful batteries
March 25, 2013 12:21 pm | by Mike Williams, Rice University | News | CommentsAccording 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.
Nanowire solar cells raise efficiency limit
March 25, 2013 8:35 am | News | CommentsThe typical solar cell efficiency limit―called the "Shockley-Queisser Limit"―has for many years has been a landmark for solar cell efficiency. Scientists from at the Niels Bohr Institute at the University of Copenhagen and other colleagues have shown that a single nanowire can increase this limit by concentrating sunlight up to 15 times normal intensity.
Paint-on plastic electronics
March 25, 2013 7:51 am | News | CommentsSemiconducting 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.
New solar cell design based on dots, wires
March 25, 2013 7:40 am | by David L. Chandler, MIT News Office | News | CommentsUsing exotic particles called quantum dots as the basis for a photovoltaic cell is not a new idea, but attempts to make such devices have not yet achieved sufficiently high efficiency in converting sunlight to power. A new wrinkle added by a team of researchers at Massachusetts Institute of Technology—embedding the quantum dots within a forest of nanowires—promises to provide a significant boost.
N.Y. strikes nanotechnology deal with Israel
March 21, 2013 11:32 am | by The Associated Press | News | CommentsNew York state has a new agreement with Israel aimed at increasing collaboration on nanotechnology research. Gov. Andrew Cuomo announced Wednesday that his administration has signed a memorandum of understanding with Israel that will expand technological and economic relations in nanotechnology, which involves manipulating matter on an atomic scale.
Researchers trap light, improve laser potential of MEH-PPV polymer
March 21, 2013 8:33 am | News | CommentsResearchers from North Carolina State University have come up with a low-cost way to enhance a polymer called MEH-PPV's ability to confine light, advancing efforts to use the material to convert electricity into laser light for use in photonic devices.
X-ray laser explores how to write data with light
March 21, 2013 7:52 am | News | CommentsUsing laser light to read and write magnetic data by quickly flipping tiny magnetic domains could help keep pace with the demand for faster computing devices. Now experiments with SLAC National Accelerator Laboratory's Linac Coherent Light Source X-ray laser have given scientists their first detailed look at how light controls the first trillionth of a second of this process, known as all-optical magnetic switching.
Magnetic nano-droplet discovery presents telecom opportunity
March 20, 2013 5:06 pm | News | CommentsA team that includes researchers from Sweden has successfully created a magnetic soliton, a spin torque-generated nano-droplet that could lead to technological innovation in such areas as mobile telecommunications. This construct was first theorized 35 years ago and scientists have long believed that they exist in magnetic environments, but until now they had never been observed
Researchers use simple sonochemical method to synthesize zinc oxide nanostructures
March 20, 2013 7:51 am | News | CommentsA research team from the U.S., Iran, and Malaysia has produced of zinc oxide nanostructures by using zinc acetate as the initiator through a new, fast, and simple sonochemical method. The chemicals required for the synthesis of zinc oxide include zinc acetate salt, sodium hydroxide, and ammonia solution without the need to other structure controlling agents or surfactants. It does not require high temperature or highly toxic materials.
3D printing turns models into reality
March 19, 2013 10:23 am | by Steve Koppes, University of Chicago | News | CommentsProfessor Heinrich Jaeger's laboratory at the University of Chicago uses 3D printing to test complex qualities and phenomona of shapes made via computer. One such phenomenon is jamming, in which aggregates of randomly placed particles, including spheres or more complicated shapes, or even molecules, transition from fluid-like to solid-like behavior. Recent analysis shows how the properties of a jammed material can be tuned by changing the shape of the constituent particles.
Honeycomb nets from bismuth cubes
March 19, 2013 8:07 am | News | CommentsResearchers from Dresden have discovered a new material that conducts electric currents without loss of power over its edges and remains an insulator in its interior. The material is made out of bismuth cubes packed in a honeycomb motif that is known from the graphene structure. As opposed to graphene, the new material exhibits its peculiar electrical property at room temperature, giving it promise for applications in nanoelectronics.
Study: One can affect an atom’s spin by adjusting the way it is measured
March 18, 2013 4:31 pm | News | CommentsJust as our eyes observe the world by absorbing the photons—light particles—scattered in our direction by objects, researchers at the Weizmann Institute have observed the process of spin collapse in atoms by measuring scattered photons. In recent research results, they showed that the direction that a photon takes as it leaves the atom is the direction that the spin adopts when superposition—multiple realities that exist only so long as the system is not observed or measured in any way—collapses.
Researchers synthesize negative-charge carrying molecular structures
March 18, 2013 4:24 pm | News | CommentsUniversity of Oregon chemists have synthesized organic molecular structures that move both positive and negative electrical charges—a highly desired but often difficult combination to achieve in current efforts to create highly flexible electronic devices and other new-age technologies.
Researchers improve laser potential of MEH-PPV polymer
March 18, 2013 1:45 pm | News | CommentsMEH-PPV is a low-cost polymer that can be integrated with silicon chips, and researchers have sought to use it to convert electricity into laser light for use in photonic devices. However, attempts to do this have failed because the amount of electricity needed to generate laser light in MEH-PPV was so high that it caused the material to degrade. Researchers have recently come up with a low-cost way to enhance MEH-PPV’s ability to confine light, protecting the material.
Engineers make vibration sensor in the quantum world
March 18, 2013 9:21 am | News | CommentsResearchers in France and Germany have found a way to combine both carbon nanotubes with magnetic molecules on the atomic level to build a quantum mechanical system that acts as a vibration sensor. In their experiment the researchers used a carbon nanotube that was mounted between two metal electrodes, spanned a distance of about 1 µm, and could vibrate mechanically.
Scientists create flexible mineral inspired by deep-sea sponges
March 15, 2013 11:10 am | News | CommentsImitating the structural elements found in most sea sponges, researchers in Germany have created a new synthetic hybrid material that is extremely flexible yet has a mineral content of almost 90%. They recreated the sponge’s spicules using natural calcium carbonate and integrated a protein of the sponge. The invention is even more flexible than its natural counterpart.
