4 ms·

> Imagine dropping millions of these from a drone, carpeting a city. Doesn't it still need a source of power?

roywiggins 5y ago
There's at least some power to be pulled from ambient radio waves. No idea if it would be enough to power these things. https://phys.org/news/2017-08-ambient-energy-power-internet.html https://phys.org/news/2017-08-ambient-energy-power-internet.... Or combine it with photovoltaics: https://www.smart2zero.com/news/self-powered-camera-sensor-combines-imaging-energy-harvesting https://www.smart2zero.com/news/self-powered-camera-sensor-c...
JoeAltmaier 5y ago
RFID tags have no power source, and can do significant processing. As others mention, ambient electromagnetic fields can be harvested with a loop antenna.
- fallat 5y ago
  What processing can an RFID do? AFAIK RFID can only store and send data, and are pretty "dumb".
  - _jal 5y ago
    For instance, https://www.usenix.org/legacy/events/nsdi11/tech/full_papers/Buettner.pdf https://www.usenix.org/legacy/events/nsdi11/tech/full_papers...
  - anaganisk 5y ago
    I remember watching a docu in Netflix about spies where they show a deice that could record and transmit sound, using same technology.
    - xijingpooh 5y ago
      That's how the Soviets bugged the US embassy in Moscow. With a resonant circuit w/o a power source and a reflected RF beam.
    - fallat 5y ago
      It's not processing though? It's acting like a mirror or a polaroid? Do those process?...
    - dredmorbius 5y ago
      The "Chrysostom" Great Seal Bug, 1945, USSR, created by Léon Theremin, who also invented the early electronic musical instrument bearing his name. The bug remained installed in the US Embassador's office for 15 years, though it was recognised as a listening device in 1952. https://hackaday.com/2015/12/08/theremins-bug/ https://hackaday.com/2015/12/08/theremins-bug/ https://www.algora.com/Algora_blog/2021/02/07/the-great-seal-bug-how-the-soviet-union-spied-on-the-us-embassy https://www.algora.com/Algora_blog/2021/02/07/the-great-seal...
- trompetenaccoun 5y ago
  It's theoretically possible but they'd have to put up antennas all over our cities, emitting ultra high frequency signals. The distance this would work over would be very short as well.

There's at least some power to be pulled from ambient radio waves. No idea if it would be enough to power these things. https://phys.org/news/2017-08-ambient-energy-power-internet.html https://phys.org/news/2017-08-ambient-energy-power-internet.... Or combine it with photovoltaics: https://www.smart2zero.com/news/self-powered-camera-sensor-combines-imaging-energy-harvesting https://www.smart2zero.com/news/self-powered-camera-sensor-c...

JoeAltmaier 5y ago

RFID tags have no power source, and can do significant processing. As others mention, ambient electromagnetic fields can be harvested with a loop antenna.

fallat 5y ago
What processing can an RFID do? AFAIK RFID can only store and send data, and are pretty "dumb".
- _jal 5y ago
  For instance, https://www.usenix.org/legacy/events/nsdi11/tech/full_papers/Buettner.pdf https://www.usenix.org/legacy/events/nsdi11/tech/full_papers...
- anaganisk 5y ago
  I remember watching a docu in Netflix about spies where they show a deice that could record and transmit sound, using same technology.
  - xijingpooh 5y ago
    That's how the Soviets bugged the US embassy in Moscow. With a resonant circuit w/o a power source and a reflected RF beam.
  - fallat 5y ago
    It's not processing though? It's acting like a mirror or a polaroid? Do those process?...
  - dredmorbius 5y ago
    The "Chrysostom" Great Seal Bug, 1945, USSR, created by Léon Theremin, who also invented the early electronic musical instrument bearing his name. The bug remained installed in the US Embassador's office for 15 years, though it was recognised as a listening device in 1952. https://hackaday.com/2015/12/08/theremins-bug/ https://hackaday.com/2015/12/08/theremins-bug/ https://www.algora.com/Algora_blog/2021/02/07/the-great-seal-bug-how-the-soviet-union-spied-on-the-us-embassy https://www.algora.com/Algora_blog/2021/02/07/the-great-seal...
trompetenaccoun 5y ago
It's theoretically possible but they'd have to put up antennas all over our cities, emitting ultra high frequency signals. The distance this would work over would be very short as well.