Engineers from the University of Washington have discovered how to use the untapped energy transmitted by Wi-Fi routers to power devices. The technology is called Power over Wi-Fi (PoWiFi) and the final paper will be presented next month at the CoNEXT 2015 meeting in Germany.

PoWiFi’s prototype combines a device that delivers power on multiple channels, and antennae that can be attached to devices, harvest energy and turn it into DC current.

The radio waves emitted by Wi-Fi routers transmit about 1 watt of power, which is used to carry data to devices. In comparison, a typical smartphone charge requires 5 watts of power. Routers send signals intermittently when data is requested by a device, so the team developed an optimized version that sends out power packets continuously over the channels not used by the data.

Although these experiments are really promising, the devices used only needed small amounts of power. Before Wi-Fi charging becomes readily available, there are significant improvements needed to guarantee stability and reliability from the router.

bbabo.Net