Researchers discover battery-free technology which harvests power from radio and Wi-Fi signals for low-powered devices
tomshardware.com
cross-posted from: https://lemmy.ml/post/18426215
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cross-posted from: https://lemmy.ml/post/18426215
In no way is this a discovery.
This is what crystal diode radios are from the '40s.
Some guy built one in Japan, it's basically just a thousand transceivers in a box hooked up to a USB port harvesting radio/wifi signals.
Here's a guy using them to make light:
It's super cool, but not a discovery.
https://youtu.be/_pm2tLN6KOQ?si=ppEv2PkdK_MHFrw6
A friend of mine was working on a car chassis and that thing suddenly started to receive radio. You could faintly hear it coming from the chassis and not from somewhere else. We thought we were going crazy. Touching the chassis made it go away.
When I was a kid, I got a stereo system for my birthday one year alongside two big speakers. The speakers, if they stayed powered while the stereo was off, would receive faint traces of radio signal. So round midnight when the house is quiet I could always hear faint voices, just barely loud enough to hear, but quiet enough to make you wonder if you're really hearing it. Nearly scared the dick off me, I thought my parents gave me a haunted stereo. No, turns out it was just haunted by the ghosts of local AM radio.
Haha, that's so cool.
This would be neat for a bunch of passive IoT buttons. No need for a piezo to generate power, good for a couple presses at a time, just simple stuff like that.
Charge up a capacitor and allow a single button press to send a radio signal. Or maybe have enough power to send a WiFi signal.
You're right, that would be the preferred application atm.
I wonder if it could power a sensor. Something like a soil dampness or thermometer, where you only need a few updates per day. Could be pretty cool for passive monitoring applications.
I remember making a crystal diode radio with my dad as a kid. You can still buy kits for those.
From Radio Shack?!