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Researchers Power a Security Camera With Wi-Fi Signals
Kristine Lofgren writes: Nikola Tesla dreamed of a world full of free, wireless power. While he never accomplished that dream during his lifetime, researchers at the University of Washington are doing their part to make it a reality with a breakthrough in wi-fi powered electronics. Dubbed PoWi-Fi, the team led by Vamsi Talla were able to recharge and maintain consistent low-level power over a number of different devices at distances of up to 28 feet.
If you RTFA, they didn't just use a regular WiFi access point. They modified the AP so that in addition to one channel carrying data, there were another two radios on non-overlapping channels transmitting noise. Great for powering your thermostat, but horrible for your neighbors.
The spectrum is already crowded with most homes transmitting one channel - imagine if everyone stated transmitting three. The noise floor would go up drastically and WiFi would be rendered near inoperable.
You'd be able to detect them, since all other WIFI signals in the vicinity would be horribly degraded by the modified AP spewing continuous noise on several channels.
They managed to take one 174x144 pixel black and white picture every 35 minutes at a distance of 5 metres. No transmitting of the image anywhere, it's stored locally.
You'd probably be able to do much better with one of those small solar cells from a calculator.
Cameras actually used to work like that! Of course, they used chemicals instead of electricity and each 'sensor' only worked for one image...
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
It's still in the early stages of research, but yes you can power a camera from light entering the lens.