Instructables

ambient backscatter

(Ambient backscatter: Free energy harvesting from TV signals, to power a ubiquitous internet of things)

Has anyone ever tried this? This would most surely make a popular project for the site, but I would love to see if there is a diagram for this in particular with a practical application.



Not very useful for most people. Best applications for something like this would be field researchers needing to gather data form a large array of closely placed sensors. There isn't much use for the average person. For one the range of the transmission isn't very far. Plus there is a high chance of signal interference rendering the device useless. The power gathered from radio transmissions is extremely weak and would not support any other applications. This is still an experimental project and likely has a long way to go. Chances of seeing any related projects here or someone working out how it all works on there own is very slim.
I will just leave this right here
http://gizmodo.com/battery-free-wireless-devices-let-you-send-texts-after-1124345931
Hmmm....

...hopefully... ...could... Imagine a future...

And, though they have worked out how to send a message, they haven't cracked the power required to actually write it.

Interesting concept for semi-passive sensors, though.