Keeping your power-hungry smartphones charged with cables and portable batteries may be a thing of the past as two engineering students have figured out a way to charge them with Wi-Fi. Allen Hawkes and Alexander Katko from Duke University’s Pratt School of Engineering have developed a device with metamaterials that captures energy waves from wireless Internet and converts them into electrical current. The students say the power-harvesting device is even more efficient than a USB charger and it has similar output to modern solar panels.
The device can wirelessly convert Wi-Fi’s microwave signals into direct current voltage to recharge a cell phone battery or other small electronic devices. Key to this power harvester are the metamaterials, which are engineered structures that can capture various forms of wave energy and tune them for useful applications. These energy sources could include satellite signals, sound signals or Wi-Fi signals.
In an age when we are swimming in a sea of wireless broadband and cellular networks, this device could allow us to keep charging our phones no matter where we are. What’s more, it is actually more efficient than plugging in your device. In their tests, Hawkes and Katko wired together a series of five fiberglass and copper energy conductors on a circuit board to convert microwaves into 7.3 volts of electricity, whereas USB is limited to 5 volts. It also has an energy conversion efficiency of 36.8 percent—comparable to a solar cell.
The researchers say the material could also be applied to make our homes more energy efficient. A metamaterial coating could be applied to the ceiling of a room to redirect and recover a Wi-Fi signal that would otherwise be lost. However, the technology is still in progress. Hawkes and Katkoare are working on perfecting the technology to make the metamaterials operable inside of a cell phone.
via Daily Mail
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