At the University of Utah, a mechanical engineer named Mathieu Francoeur has found a slight technicality when it comes to a principle that allows wasted heat to be recycled into usable electricity. This presumably amazing device-which has been dubbed a Near-Field Radiative Heat Transfer Device-collects heat by simply placing two silicon surfaces close to one another until they're almost touching. In order to store heat, this device blows past the blackbody limit.
In the future, this setup might not only be able to cool down mobile devices like laptops and smartphones but it may also be able to channel their heat into more battery life.
A blackbody is anything that has the capabilities to basically suck up all the electromagnetic radiation that it comes in contact with. And, so as to remain in safe balance, the blackbody must also release radiation at the same rate. This is essentially the reason why stoves are required to be black.
Although the blackbody limit is a theory, it informs us of the quantity of heat that may be discharged from an object. This is thought to be a no-limit ceiling once the placing of the objects is small enough.
With the help of his colleagues, Francoeur developed a 5mm-by-5mm chip made of two silicon wafers spaced by a nanoscopic gap only 100 nanometers thick - that's one thousandth the thickness of a human hair.
"Nothing can emit more radiation than the blackbody limit," he said. "But when we go to the nanoscale, you can."
After placing the chip in a vacuum, the researchers began by heating one side of the chip and cooling the other side separated by a tiny gap. This essentially created a heat flux that can be converted into electricity. While this alone is not necessarily groundbreaking, the new study finds its life is in its evidence of placing two silicon surfaces in close enough proximity to achieve this effect without them ever coming into contact with each other. The nearer the surfaces are to one another, the more electricity can be generated.
The United States loses about 66 percent of the energy it consumes through the emitting of heat from appliances and gadgets. Francoeur predicts that his device will be used in the future to cool gadgets and subsequently produce extra battery power. He estimates that battery life could potentially be improved by nearly 50 percent using this technology.
"You put the heat back into the system as electricity," he said. "Right now, we're just dumping it into the atmosphere. It's heating up your room, for example, and then you use your AC to cool your room, which wastes more energy."