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Researchers Power a Security Camera With Wi-Fi Signals

Posted by samzenpus on from the negative-and-positive-waves dept.

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.

5 of 59 comments (clear)

  1. Gee this AGAIN? by bobbied · · Score: 2, Informative

    Nothing new to see, move on...

    RF back-scatter energy collection has been used since Tesla (not the company, the scientist) invented it nearly 100 years ago.... So now you can park your web camera near a WiFi RF source and get some images out of it? Color me surprised. How quaint...

    --
    "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
    1. Re:Gee this AGAIN? by DerekLyons · · Score: 4, Informative

      I dont understand why they arent powering it with the light entering the aperture. Surely a camera could be powered by some of the light its capturing?

      It's still in the early stages of research, but yes you can power a camera from light entering the lens.

  2. Interesting experiment but deeply flawed by aXis100 · · Score: 5, Informative

    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.

    1. Re:Interesting experiment but deeply flawed by petherfile · · Score: 3, Informative

      Unless they are trying to find a free channel for data and there just isn't one because 6 people around you are doing this all on different channels. Allocation of another part of the spectrum for power transmission: much better idea than trying to use the same ones as for data.

        Using incidental energy that is being used for data transmission anyway - nothing wrong with that. Flooding data channels with noise, not so nice for other people around you.

  3. Re:Spy Cams by viperidaenz · · Score: 5, Informative

    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.