Engineers from the University of Washington have developed a system that harvests energy from Wi-Fi signals in order to power small devices, and they call it the PoWiFi system (Power Over Wi-Fi). The team will be presenting at the Association for Computing Machinery’s CoNEXT 2015 conference.
In the press release, lead author Vamsi Talla shared some details on the system, saying "For the first time we've shown that you can use Wi-Fi devices to power the sensors in cameras and other devices. We also made a system that can co-exist as a Wi-Fi router and a power source -- it doesn't degrade the quality of your Wi-Fi signals while it's powering devices."
The research team found that untapped, ambient Wi-Fi signals can often come close to supplying enough energy to low-power devices. These signals can be optimized to deliver “power packets” without loss in quality and speed.
As networked devices become smaller and smaller, there less and less room left for batteries. The option to power these tiny devices over Wi-Fi signals opens the possibility for even more flexible applications, particularly in the industry of the Internet of Things.Co-author Shyam Gollakota optimistic about the technology powering larger devices, saying "In the future, PoWi-Fi could leverage technology power scaling to further improve the efficiency of the system to enable operation at larger distances and power numerous more sensors and applications."
One of the problems with developing this tech is that Wi-Fi broadcasts are not continuous. Rather, routers tend to broadcast on a single channel in bursts. The team notes that this provides enough power for the sensor; however, as soon as the broadcast stops, the voltages drop.
Ultimately, this is where the idea came from. "Why not program the router to broadcast noise when it is not broadcasting information and employ adjacent Wi-Fi channels to carry it so that it doesn’t interfere with data rates,” Talla thought.
The a new breakthrough was born.