A team of researchers from the University of Washington (UW) are working on perfecting a method of charging electronic devices using ambient Wi-Fi signals. They technology, PoWiFi (power over Wi-Fi) makes a small change to routers, so they send out a constant signal that can be harnessed and converted into DC power by a “harvester”. The idea isn’t new, embodied by Energous’s WattUp, but the UW scientists’ PoWiFi works with pre-existing hardware, so there is no need to buy a separate device. Their modified routers are able to send data and power over the same signal.
It turns out that a small amount of power is already transmitted by Wi-Fi signals. The FCC guidelines allow up to 1 watt, which is used to carry data. This isn’t much, considering that a standard mobile device charger will carry a 5-watt output. While, this method is unfit for powering a smartphone, it is well-suited to charge low-energy devices such as fitness trackers.
One of the successes from researcher Vamsi Talla is the Wi-Fi-Powered camera pictured above. The camera was placed 17 feet from a PoWiFi router, and collected enough power to take a picture every 35 minutes. Coincidentally, the majority of PoWiFi users (in a small sample size of 6 people) did not notice any change in Internet speed.
Source: Popular Science