

New Printable Antenna Harvests Energy From Air - mimeoconnect
http://developer.mimeo.com/blog/blog_detail.php?ID=149

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bradleyland
It's understandable that content needs to be watered down for accessibility
purposes, but this is taking it a bit far. The energy isn't harvested from the
"air", it's harvested from background electromagnetic activity. You could do
this in a vacuum. No air required.

I wish the artcile had some more specifics on the efficiency of the antennae.
Is there something unique about the design outside of the fact that they're
printed on paper?

For what it's worth, if you've ever used an FM radio, you've "harvested energy
from air". The antenna on your FM radio detects fluctuations in radio waves,
which are a type of electromagnet field. FM signal output is measured in
watts. If you were to put your hand on a powerful RF transmission antenna, you
will get burned. That's energy. The key thing to understand is that you're
talking about very, very small amounts of energy as you move away from the
transmitter. That doesn't appear to have changed here, as they're talking
about microwatts.

Interesting, but the title strikes me as link bait.

~~~
zwieback
I had the same reaction and looked at the linked Georgia Tech article for more
info. It's pretty much the same except it mentions carbon nanotubes as well as
silver nanoparticles - woohoo! Maybe they'll use it to power fuzzy neural
networks.

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guscost
This is very similar to the technology used in simple crystal radios, which
also power themselves.

<http://en.wikipedia.org/wiki/Crystal_radio>

~~~
dimitar
Well, crystal radios are electrically passive but usually the power was low
and thus you couldn't produce enough "volume". So people interestingly built
pneumatic amplifiers (the principles are equivalent to electric amplifiers, I
have studied some pneumatic devices and sometimes they are modeled with
electrical circuits for convenience) using gas lamps, which were more abundant
than batteries or mains at the time.

This source of the article claims they will produce milliwatt power and the
power of crystal radios circuits is measured in nanowatts. This is 1000 or 1
000 000 times more.

They apparently do this by using multiple frequency ranges, while a cristal
radio includes a adjustable electronic filter to frequencies, cutting the ones
off above a particular, well cutoff frequency, you also don't want other
signals of the same range in radios because you will create noise in your
headphones.

This is the basic principle, I'm sure there are some technical errors
somewhere, but I'm still a student :-).

------
dimitar
[http://gtresearchnews.gatech.edu/device-captures-ambient-
ene...](http://gtresearchnews.gatech.edu/device-captures-ambient-energy/) \- I
find the source much more interesting :-)

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meow
Nikola Tesla will be proud :)
[http://en.wikipedia.org/wiki/File:TeslaWirelessPower1891_adj...](http://en.wikipedia.org/wiki/File:TeslaWirelessPower1891_adjusted.png)

