Friday, July 10, 2009

This week in nanotechnology July 4-10, 2009

Computer simulations shed light on nanosized minerals. The red and blue images appear ghostly, like a fleeting glimpse of something that’s never been seen before – which is true. Using computer simulations, Berkeley Lab scientists have developed the first predicted images of water molecules surrounding a nanoparticle, in this case an iron-oxide mineral called hematite.

In nanoelectronics, the use of molecules as elements in electronic circuits shows great potential. One of the central challenges up until now has been that most molecules only start to conduct once a large voltage has been applied. An international research team has shown that molecules containing an odd number of electrons are much more conductive at low bias voltages.

On to new findings in improving solar panel efficiency. In 1907 German physicist Gustav Mie realized that tiny metal particles in stained glass scattered light in ways that produced beautiful colors. Now, a related interplay between light and matter explains why incredibly thin nanowires made of semiconductors like germanium may prove to be effective components for solar cells. Combining Mie's work with more recent theory, the Stanford team has discerned how to tune and improve the light absorption efficiency of the wires. Over at the Berkeley Lab, researchers have demonstrated a way to fabricate efficient solar cells from low-cost and flexible materials. The new design grows optically active semiconductors in arrays of nanoscale pillars, each a single crystal, with dimensions measured in nanometers

In nanomedicine, a study of human colon, pancreatic and lung cells is the first to report that cancer cells and their non-cancerous cell neighbors, although quite different under the microscope, share very similar structural abnormalities on the nanoscale level. The most striking findings were that these nanoscale alterations occurred at some distance from the tumor and, importantly, could be identified by assessing more easily accessible tissue, such as the cheek for lung cancer detection.

Researchers in Switzerland have now demonstrated novel cell biology applications using hollow force-controlled AFM cantilevers – a new device they have called FluidFM. This novel device combines AFM and nanofluidics for single cell applications.

Nanotoxicology studies on aquatic ecosystems have been scarce – although everything winds up in the water eventually. Now a team of Canadian scientists and engineers, led by the University of Alberta and the National Research Council of Canada, will collaborate on a $3.39 million, three-year study to assess the potential effects of nanoparticles in specific water environments.

Speaking about possible nanotechnology risks, there still is a lot we don't know yet about the environmental, health and safety impact of nanomaterials, but at least scientists are making progress in identifying the gaps – the 'known unknowns' as they call it.

Purification of carbon nanotubes still is a major headache for CNT producers. A team of researchers from DuPont and Lehigh University says it has developed a DNA-based method that sorts and separates specific types of CNTs from a mixture.

Not really nanotechnology but still cool stuff: Physicists have overcome a major hurdle in quantum computer development, having devised a viable way to manipulate a single "bit" in a quantum processor without disturbing the information stored in its neighbors. The approach, which makes novel use of polarized light to create effective magnetic fields, could bring the long-sought computers a step closer to reality.

And finally, for all you Harry Potter fans, a new metamaterial brings us closer to the dream of invisibility. A group of researchers in Spain have designed a device, called a dc metamaterial, which makes objects invisible under certain light by making the inside of the magnetic field zero but not altering the exterior field. The device, which up to date has only been studied in theoretical works, thus acts as an invisibility cloak, making the object completely undetectable to these waves.