Friday, March 25, 2011

This week in nanotechnology - March 25, 2011

Researchers at the University of Illinois have developed a three-dimensional nanostructure for battery cathodes that allows for dramatically faster charging and discharging without sacrificing energy storage capacity. This system gives you capacitor-like power with battery-like energy.

Researchers at Rice University have created a synthetic material that gets stronger from repeated stress much like the body strengthens bones and muscles after repeated workouts. The trick, it seems, lies in the complex, dynamic interface between nanostructures and polymers in carefully engineered nanocomposite materials.

Graphene study raises question: Is space like a chessboard? Physicists at UCLA set out to design a better transistor and ended up discovering a new way to think about the structure of space. Space is usually considered infinitely divisible — given any two positions, there is always a position halfway between. But in a recent study aimed at developing ultra-fast transistors using graphene, researchers from the UCLA Department of Physics and Astronomy and the California NanoSystems Institute show that dividing space into discrete locations, like a chessboard, may explain how point-like electrons, which have no finite radius, manage to carry their intrinsic angular momentum, or "spin.
spinning electrons
The standard cartoon of an electron shows a spinning sphere with positive or negative angular momentum, as illustrated in blue or gold above. However, such cartoons are fundamentally misleading: compelling experimental evidence indicates that electrons are ideal point particles, with no finite radius or internal structure that could possibly "spin".

Like copper wires in our everyday life, nanowires are envisioned to act as interconnecting elements in future electronic circuits on the nanoscale. Moreover, when made from semiconductors these nanowires not only transport electric current along their axis but also can very efficiently emit light. Researchers in Munich have found a way to combine these two fundamental properties.

Princeton researchers have invented an extremely sensitive sensor that opens up new ways to detect a wide range of substances, from tell-tale signs of cancer to hidden explosives. The sensor, which is the most sensitive of its kind to date, relies on a completely new architecture and fabrication technique. The device boosts faint signals generated by the scattering of laser light from a material placed on it, allowing the identification of various substances based on the color of light they reflect. The sample could be as small as a single molecule.