Professor's Battery Research Noted in Nature

DISCOVERY MAY BE USED TO POWER IPODS, ELECTRIC CARS IN A MORE EFFICIENT WAY

College of Arts & Sciences physics professor Stewart E. Barnes, working with researchers at the Universities of Tokyo and Tohoku, Japan, has demonstrated that development of a “spin battery”—predicated on the forces acting on the spin of electrons and charged by applying a large magnetic field to microscopic devices called nanomagnets—is possible. The scientists’ research was published in the March 8, 2009, issue of Nature.

This discovery could potentially move technology a major step forward, as it holds promise for producing batteries that are highly efficient both in producing and storing energy. And it may result in the production of much faster and less expensive computer hard drives that, with no moving parts, consume less energy than current models. It is even conceivable that future spin batteries could be harnessed to power cars.

The science behind this technology is that nanomagnets would induce the electromotive force, or voltage—unlike in conventional batteries, which rely on chemistry. Whether in an iPod or an electric car, when something is turned on a chemical reaction occurs in an existing battery that produces an electric current. The spin battery would instead convert the magnetic energy stored in nanomagnets directly to electrical energy.

Barnes and his collaborators in Japan concluded that, like a winding up a toy car, the spin battery could be “wound up“ by applying a large magnetic field, and, despite its tiny size, could have large-scale manifestations. “We had anticipated the effect, but the device produced a voltage over a hundred times too big and for tens of minutes, rather than for milliseconds, as we had expected,” said Barnes.

The technology could have widespread application. “There are magnets hidden away in many things,” he noted. “For example, there are several in a mobile telephone, many in a car, and they are what keeps your refrigerator closed. There are so many that even a small change in our understanding of how they work, possibly leading to only a small improvement in future machines, could have significant energy and financial impacts.”

And “although the actual device has a diameter about that of a human hair,” Barnes added, “it can produce and store energy at densities large enough that a scaled-up version could potentially run a car for miles. The possibilities are endless.”