14 DAY TRIAL // A group of investigators at the Ohio State University (OSU), in Columbus, announces the development of a technique that enables physicists to amplify a new magnetic effect that converts heat into electricity more than 1,000 times over.
This could very well be the first step towards bringing future electricity generation technologies closer to reality, and more practical. If an approach that can take advantage of this effect is developed, then we could gain access to a new, viable class of power sources.
Inside electronic devices, for example, chips and processors generate an enormous amount of heat, which currently requires large fans and coolers to remove. By using the newly-discovered magnetic effect, it may become possible to turn that heat into electricity, to be fed back into the devices.
This would significantly reduce the amount of power electronics and other machines would consume, since a large portion of their requirements would be fulfilled from their own heat emissions. Physicists refer to this type of conversion as the spin Seebeck effect.
It works by having the spin of electrons create an electrical current in magnetic materials. What the OSU team did was find a way of obtaining this effect in a non-magnetic semiconductor. At the same time, they tweaked the process so that it produces substantially more electricity.
The amplified phenomenon is now called the giant spin-Seebeck effect. Investigators at the university, led by OSU Eminent Scholar in Nanotechnology Joseph Heremans, have already applied for obtaining patents on the technology, and some of its derivatives.
According to a paper the research team published in this week's issue of the top scientific journal Nature, the voltages produced by this effect are small, a few microvolts. However, after the new study, the tweaked semiconductors can release up to a few millivolts.
While this may not seem like much for current applications, the research did demonstrate a 1,000-fold increase in voltage, and a 1-million-fold increase in power. OSU scientists are convinced that this line of research will be developed even further in upcoming studies.
“It's really a new generation of heat engine. In the 1700s we had Steam engines, in the 1800s we had gas engines, in the 1900s we had the first thermoelectric materials, and now we're doing the same thing with magnetics,” says Heremans.
The expert, who also holds an appointment as a professor of mechanical engineering and of physics at OSU, says that the devices will also be extremely reliable, since they will have no moving parts whatsoever.
The new study was made possible by grants secured from the US National Science Foundation (NSF) and the Department of Energy (DOE).