Something like BatteryFree from A4Tech?

http://a4tech.com/ennew/product.asp?cid=142&scid=92&id=265

Regarding wireless power from a mouspad, something like a wacom tablet mouse?

If you’d like to read about an open design, check out this one where any device placed inside the backpack is wirelessly recharged:

http://www.computer.org/portal/web/csdl/doi/10.1109/ISWC.2008.4911592

Or, if you prefer robots operating on a surface:

http://www.hizook.com/blog/2008/10/07/wirelessly-powering-swarm-robots

it’s the exact same old principle we’re using when building transformer,instead of a metal core,we have an Air one,so basicly,we could not just transmit power but also change it’s voltage.
static electricity radio would love being by the side of this.

@ Wolvenmoon

Look into Tesla’s work and experiments.

I’m pretty sure some of his stuff could be scaled down to meet our needs.

Unfortunately my degree is in business rather than hard science or I would pursue it myself.

Makes for interesting reading though.

@Dad
Tesla spent all his life trying to grab electricity from the air, and people have spent another 100 years studying his work trying to do it. I don’t think any one of us is going to pull that off…
Though i thought i saw something new lately about using existing radio waves to help top off the charge on devices…
-Taylor

I’m gonna build one in my phone!
great hack!

this one is better:

@ therian

I know eh.

It’s nothing more than a radio…and a transmitter. Except that no information is being transmitted.

Throw a couple LEDs in a tuned circuit and everyone starts drooling.

That said it could be useful. But realistically there are many problems with this form of charging/ power transfer. EMI anyone?

@octel: in fact, thats the big advantage of this kind of application: you need only one charger and every device includes a coil matching its own specs. much better than having 100 different chargers for all your gadgets as is the current status quo!

Old news!
Published May 2009.

Take the wires of the telephone poles and embed them in the roads, run our hybrid. A new ifrastructure idea? Not.

What’s the relationship between the frequency and the capacitors? I mean, how would you know what cap to use if you were oscillating at a different frequency?

It’s called induction, it was discovered aroud the same time as fire.

[Quote almost_three]
>Look ma, no wires

What’d ya’ mean no wires? Looks like about 50 feet of wire to me!

I was totally thinking the same thing. Reminds me of h.a.d’s Dyson entry.
http://hackaday.com/2009/10/14/it-has-blades-dysons-little-white-lie/

This is NOT what MIT did. This is a transformer, not a magnetically coupled resonance device.

He is on the right track, but what he needed to do was use Frequency = 1/(2p(LC)^0.5) to choose his capacitance and the function generator frequency.

This resonant frequency is when the inductors and capacitors cancel out each other’s impedance and allows for the high efficiency at distance.

Google and Wikipedia ftw!

Apparently the idea is that since the magnetic field is oscillating resonantly there is a very low loss in the source. The placement of the sink is not very important in this sense, it will leech whatever it can, and in the lossless situation, the energy the sink doesn’t absorb this cycle will still be available the next cycle. Very neat indeed.

PS. after numerous years as a nethabitant I still haven’t learned how to search before letting my yapper fly. Let this be a lesson to all.

Now that you guys are talking about resonance I would like to pose a question that has been bugging me. Why do these types of coils couple so efficiently? That is, I would have thought, given only a transmitter, that the energy would propagate away and be lost to space. If true, how could any receiver, unless it encloses the transmitter (which is not feasible), approach the efficiency of resonating coils?

On possible explanation is that the field around a resonating coil collapses back into the coil instead of propagating out into space. Which begs the alternate question: How does any energy propagate to a receiving coil?

I have looked at Dr Soljacic’s (of MIT) publications – which are well beyond me. The answer is probably there, but hidden in the equations.

Anyone?