If you're a techie, then you've probably heard of PoE (power over Ethernet), which is a method of powering network devices using the same Ethernet cable that provides the device with Internet signals.
But wires are... so out. Everyone wants wireless things nowadays.
A group of scientists at the University of Washington have managed to harness the power of wireless signals from a networking medium that you're probably already very familiar with; Wi-Fi.
Playing off of the old PoE acronym, they're calling it PoWi-Fi, this is made possible by the fact that wireless radio frequency signals actually have some power in them that can be harnessed much like PoE.
The team first tested the wireless power signals with various low power electrical devices to see what Wi-Fi signals were capable of.
"The goal of the sensors is to harvest RF (radio frequency) power and convert it into DC power," says Vamsi Talla, one of the researchers involved with the project. "The second piece, the access point, there we actually developed a custom solution on it, just a software modification that would enable the access point to act both as a good power delivery source and, simultaneously, also as a good Wi-Fi router."
As explained by the project notes, using simple antennas, batteries, capacitors, and wireless signals, it was entirely possible to harness voltage from Wi-Fi signals.
The only struggle was that because wireless routers do not continually broadcast signals, instead only broadcast when a computer instructs them to, the power was not constant and would only intermittently provide small bursts of voltage.
The team got around this by configuring the wireless router to continually transmit wireless signals as noise. By doing so, the antenna used to absorb the voltage had a lot more power to soak up whether computers were sending information via the wireless router or not.
The team then decided to hook up a low power camera to the antenna to attempt to power it with the Wi-Fi signals. Surprisingly, it worked and was able to capture one image every 35 minutes using only the Wi-Fi signals. The PoWi-Fi worked well up to around 20 feet or so and could even transmit power through walls, although walls did limit the transmitting distance a little more.
This little camera was powered using only Wi-Fi signals.
Moreover, the team managed to get a reasonably nice balance between power and Wi-Fi signal, which means that the extra noise used to power your devices wouldn't have too much of a negative impact on the wireless router's ability to function as an Internet hub for your wireless devices, and also means that your home wireless router could one day act as both a power source and an Internet transmitter device.
Although it's an interesting proof of concept at this point in time, it's worth mentioning that powering the low-power devices is extremely limited with current technology. Additional research may come up with ways to optimize the Wi-Fi signals to provide additional power for much more power-hungry devices in the future.
Wireless power is just about knocking at your front door.
Source: University of Washington Study via Wired
