Friday, December 11, 2009

This week in nanotechnology, Dec 11, 2009

Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper. Simply coating a sheet of paper with ink made of carbon nanotubes and silver nanowires makes a highly conductive storage device. Like batteries, capacitors hold an electric charge, but for a shorter period of time. However, capacitors can store and discharge electricity much more rapidly than a battery.

Nanoscale machines expected to have wide application in industry, energy, medicine and other fields may someday operate far more efficiently thanks to important theoretical discoveries concerning the manipulation of famous Casimir forces. The groundbreaking research, conducted through mathematical simulations, revealed the possibility of a new class of materials able to exert a repulsive force when they are placed in extremely close proximity to each other. The repulsive force, which harnesses a quantum phenomenon known as the Casimir effect, may someday allow nanoscale machines to overcome mechanical friction.

University of Wisconsin-Madison researchers have achieved a nanoscale laser structure they anticipate will produce semiconductor lasers in the next two years that are more than twice as efficient as current continuous-wave lasers emitting in the mid-infrared. These next-generation lasers could benefit a wide range of industries, as they could be used in biomedical devices, environmental monitoring devices, missile avoidance systems and even food packaging processes.

All existing forms of electronics are built on the two-dimensional, planar surfaces of either semiconductor wafers or plates of glass. Mechanically flexible circuits based on organic semiconductors are beginning to emerge into commercial applications, but they can only be wrapped onto the surfaces of cones or cylinders – they cannot conform to spheres or any other type of surface that exhibits non-Gaussian curvature. Applications that demand conformal integration, e.g. structural or personal health monitors, advanced surgical devices, or systems that use ergonomic or bio-inspired layouts, etc., require circuit technologies in curvilinear layouts like the ones developed by the Rogers Group at the University of Illinois.

molecular dynamics simulation of a protein embedded in water


Silicon circuit mesh wrapped onto a pyramidal substrate. (Image: Rogers Group, University of Illinois)


Scientists have developed a way to rapidly manipulate and sort different cells in the blood using magnetizable liquids. Ferrofluids are comprised of magnetic nanoparticles suspended throughout a liquid carrier. They have been used in industrial applications for years, including in hard disk drives and loudspeakers. Now, a biocompatible ferrofluid – one with the right pH level and salinity so that human cells can survive in it for several hours – and a device with integrated electrodes that generate a magnetic field pattern, allowing researchers to manipulate and separate red blood cells, sickle cells and bacteria contained in this unique solution.

Using a nanoparticle from corn, a Purdue University scientist has found a way to lengthen the shelf life of many food products and sustain their health benefits by successfully modifying the phytoglycogen nanoparticle, a starchlike substance that makes up nearly 30 percent of the dry mass of some sweet corn. The modification allows the nanoparticle to attach to oils and emulsify them while also acting as a barrier to oxidation, which causes food to become rancid.