Duke Researchers: Wireless Device Converts “Lost” Energy into Electric Power

I have been wondering how long it would take for somebody to develop a means of harvesting the energy from the torrent of wireless signals that are bouncing around us these days and now it looks like it's been done.

From the abstract of their paper published in Applied Physics Letters:

We present the design and experimental implementation of a power harvesting metamaterial. A maximum of 36.8% of the incident power from a 900 MHz signal is experimentally rectified by an array of metamaterial unit cells

The device consists of an array of inexpensive copper & fiberglass cards placed inside of a waveguide. Tweaking this design to work with other wavelengths & frequencies seems like it should be pretty simple. Honestly, aside from putting the array inside of the large waveguide, it doesn't look that much different than the technology behind passive RFID (resonant inductive coupling).

link to press release

reply to post by theantediluvian


How to you distinguish between the signals that still need to get somewhere and the ones that don't?

reply to post by theantediluvian


Sounds like a reworking of what Tesla invented. How long before they work that angle too? Hehehe...

AfterInfinity
Sounds like a reworking of what Tesla invented.

Lordy lordy, I knew as soon as I read the opening post that somebody would invoke the holy name of Tesla, once again with absolutely no understanding of the topic at hand.

This "invention", if you can call it that, has been done to death ever since radio waves were first experimented with. In the same way that a crystal radio can power your headphones with no external power, this thing can do the same in the microwave region, but for powering a single LED.
Any number of other experimenters have also played with this idea in the past, for no effective real world use.

Here's one random example from youtube....


The only difference with the "invention" cited in the opening post is that they've come up with a funny antenna specifically for wifi radio.

reply to post by alfa1


Yes but a million units could convert 1000watts into 100! Go free energy go!

As pointed out by others (and in my post), this isn't exactly a revolutionary concept. I think the significance of the Duke device was the use of inexpensively produced metamaterials to boost efficiency to levels that might lead to practical applications for powering extremely low power devices through ambient energy harvesting.

reply to post by alfa1


Alfa

there was guy who designed a battery charger based on this simple tech. It used two crystal radio sets, one for the receiver and the second for the amplifier. He developed it from apassive radio that used a speaker as opposed to a low current headset.

It used to be available on Angelfire website, but that seems to have been removed now.

Will

The biggest question is, will this be legal to use? Because if it interferes with radio signals, then it could interfere with GPS units and that's a big decline stamp from that alone. Imagine you're enjoying your picnic with your wireless energy grabber thingy and an ambulance passes by, but it looses GPS signal. Not good.

I'm hoping that this really becomes something that doesn't (with perfect accuracy) interfere with useful energy. I'm already having enough issues with neighboring wifi signals, it'll be a pain if they decide to start building one of these things and suck all my bandwidth to power their light bulb. lol

But that makes me curious now about the hacking applications :X

reply to post by Em2013


There are plenty of freqs unused because of the 'loud' natural sources that one would want to tap into.

Well, but... ok, so say that microwave energy bouncing around is really good for wireless but perhaps, in the eyes of some people, not so good for human (or honeybee) health. Never mind the argument, let's just say that's the case for a minute. Would it be possible to use this kind of technology, further down the road with intentional development, to say, wrap a house in this kind of thing, so that JUST a portion of the house that needed the wireless signal from the tower is getting it, and then rest of the house is actually sort of "redirecting/absorbing" that energy, either to boost the wireless signal (so towers could send out less power) or to simply channel that bit of energy into something else?