Scientists beam power to a fitness tracker via WiFi

Wireless electricity transmission sounds... dangerous, but the ability to do it could transform the internet of things. Researchers from the University of Washington have charged a JawBone UP24 fitness tracker with nothing but ordinary WiFi. They noticed that regular, ambient WiFi was strong enough to power a variety of tiny devices, but only in micro-bursts. So, they inserted "noise" into the signals to keep the power levels steady without disrupting data transmission. Using the technique, which they dubbed "PoWi-Fi" (we vote for just "Pow-Fi") they ran a low-power surveillance camera and temperature sensor from up to 6 meters (20 feet) away from the WiFi antenna.

Not content with that, the team ratcheted up the experiments. They found that by adding a rechargeable battery, the same camera could be powered from up to 7 meters (23 feet) away, even through a brick wall. They then tested the setup in six homes and found that the modified routers had no impact on data rates in the real world. Finally, they charged a Jawbone UP24 sports tracker via PoWi-Fi to 41 percent in just two-and-a-half hours.

It's still early days, and more tests need to be done. But if you've ever changed the battery in a wireless remote camera or climate sensor, you might be able to smell the potential. If you could power those devices from a regular WiFi router instead, it could transform the internet of things into much cheaper and more usable idea.