A team of researchers at Duke University’s Pratt School of Engineering have developed an inexpensive device made out of fibreglass and copper energy conductors capable of harvesting electricity from microwave signals. Engineering students Allen Hawkes and Alexander Katko working under the guidance of Professor Steven Cummer conducted this experiment to test the efficiency of metaminerals. Metaminerals are custom made structures whose properties can be engineered. In this case the researchers worked on capturing various forms of energy and converting them into something useful. The team wired in fibreglass and copper conductors on a circuit board and was able to convert stray microwave energy into 7.3 volts of electricity. This voltage is more than enough to recharge mobile devices that use USB charging which normally requires 5 volts.


In simpler terms, this device works in the same way as a solar panel capturing ambient energy and converting it into electricity. It also has the same energy efficiency of that of solar panels which is about 40 percent. According to the team this technology has some interesting prospects for the future. They imagine consumer application like a metamaterial coating on ceiling to redirect and strengthen weak Wi-Fi signals. They imagine large scale application of this technology to power sensor networks located in inhospitable locations by capturing microwave signals from overhead satellites. They also propose that their power harvesting solution could be built into cell phones so that people living in remote areas can charge up their phones by using the microwave signals from a cellular tower.


While we wait for this innovation to be implemented so that we can power up our thirsty smartphones on the move, have a look at the following links to get a better idea on this topic, #-Link-Snipped-#, A microwave metamaterial with integrated power harvesting functionality, Metamaterialand Microwave signals turned into electrical power - BBC News.