Researchers power surveillance cam with WiFi signal

At Google I/O a few weeks ago, Google unveiled Brillo, its Internet-of-Things (IoT) platform. Brillo has been devised to compete with Samsung’s ARTIK and Apple’s HomeKit, and delivers a system where all of its devices talk to both the Internet and each other. While Google’s IoT plans involve the interaction of multiple devices, little was said about how these devices would remain charged or recharge in such 

situations, at least without needing wall chargers or external battery packs.

A team of researchers has developed Power Wi-Fi, a system that could potentially speed up IoT adoption in the next few years. Power Wi-Fi essentially recharges devices by way of a Wi-Fi router. For the experiment, University of Washington-Seattle doctoral student Vamsi Talla and fellow Sensor Systems Lab colleagues used a battery-free camera and a temperature sensor, both containing Wi-Fi chips, placed inside six homes along with Wi-Fi routers (Asus RT-AC68U) that powered the devices.

The team then modified the routers to broadcast noise and maintain constant energy to power the camera and temperature sensor. The experiment employed low-power VGA Omnivision camera and an LMT84 temperature sensor. Future possibilities include wireless charging hotspots to power fitness trackers, although security could be an issue with public Wi-Fi networks.

Power Wi-Fi may transcend traditional wall, USB, and wireless charging, but the technology seems to suffer from small power output. In Talla’s experiment, the team was only able to snap one picture on the Omnivision camera after 35 minutes of charging. Additionally, as is often the case with current wireless devices and Wi-Fi, the power “leaks during silent periods, limiting Wi-Fi’s ability to meet the minimum vintage requirements of the hardware,” the team said in its paper on the experiment.

So long charging times are a problem — as they are with solar and other emerging energy solutions. On the plus side, the team was able to maintain consistent data transmission rates while powering the camera. And with public Wi-Fi hotspots finally beginning to deliver mass Internet access to the public, power over Wi-Fi could quickly overtake wireless charging as a possible, futuristic way to charge our devices.