A group of hopefuls from The Massachusetts Institute of Technology have successfully demonstrated the transfer of electric power through a medium known as air; the process results in what MIT calls WiTricity.

MIT asks you, the reader, to “Imagine a future in which wireless power transfer is feasible: cell phones, household robots, mp3 players, laptop computers and other portable electronics capable of charging themselves without ever being plugged in.”

As if we don’t know what the man in the black mask has in store for us around the corner, MIT proceeds to announce that a team from its Physics, Electrical, and Computer Science departments have successfully demonstrated “this vision of the future.”

And the uber geeks, at this point, are probably saying, “radio waves!” Sure, given a decent size coil and a diode, and you may be pulling a few thousandths of a milliamp; but the MIT team was able to light a 60 Watt light bulb from a power source seven feet away.

The Term used, WiTricity, sounds comparative to a Nintendo power cord, but is more seriously just a brief word for wireless electricity. And it’s been coined.

I’m sure if Nikola Tesla were still around (wink), he would certainly school them in the technology, but MIT has done a decent job without Tesla’s Government seized notes - don’t get me started.

The idea spawned from Professor Marin Soljacica, who consequently led the team, as “It was probably the sixth time that month that I was awakened by my cell phone beeping to let me know that I had forgotten to charge it. It occurred to me that it would be so great if the thing took care of its own charging.”

So, an entire MIT research team and four years later, and we’re still plugging in our cell phones? Yes, but if we still can’t remember to charge them ahead of time, we’re definitely getting closer to not having to charge them at all.

Having bills to pay, the first thing that comes to mind when I think of electricity being broadcast through the air is: “how can I steal it?” or “how do I know if someone is stealing my electricity?”

And it begins; then you wake up to discover the FCC taxing you for introducing electromagnetic interference into the air; which, hasn’t been proven yet, but will be ‘thought’ to adversely affect the temperature of the earth.

But, for the time being, we will assume that there are no thieves and that the Government plays nice. All of a sudden, I’m thinking about my electricity bill. If I don’t use this transmitted energy, do I loose it?

“In contrast, WiTricity is based on using coupled resonant objects. Two resonant objects of the same resonant frequency tend to exchange energy efficiently, while interacting weakly with extraneous off-resonant objects,” wrote Franklin Hadley on MIT news.

To put it in terms only I could understand. If you’ve ever sung aloud in the bathroom, you may have noticed that one note, the one that sounded as if it were being mysteriously amplified; this effect is known as resonance.

Every size room, as well as every object, has a resonant frequency; when that particular note (frequency) travels to one side of your bathroom and back, it is in sync with the other waves of sound that are traveling to and from the walls, thus making the note sound louder.

The MIT team makes use of this process using electric and coils, rather than sound and walls.

The team explored a system of two electromagnetic resonators coupled mostly through their magnetic fields; they were able to identify the strongly coupled regime in this system, even when the distance between them was several times larger than the sizes of the resonant objects. This way, efficient power transfer was enabled.

Also noted was that this process was suitable for everday applications, as few materials interact with magnetic fields. “The fact that magnetic fields interact so weakly with biological organisms is also important for safety considerations,” Kurs, a graduate student in physics, points out.

The MIT team’s design consisted of 2 coils(shown), both copper and each a self-resonant system. Obviously, one coil transmits and the other receives; but instead of transmitting electromagnetic waves, it fills the space around it with a magnetic field. (a big electromagnet)

Since each coil is designed to resonate with each other, the strong interaction allows the 2nd unit (the bathroom) to effectively pick up on the signal (that one sung note) and therefore return the current through the coils - very similar to the way a transformer works.

The magnetic field that is transmitted by the sending coil oscillates at MHz frequencies to exhibit a changing magnetic field, thus allowing for induction.

Moffatt, an MIT undergraduate in physics, explains: “The crucial advantage of using the non-radiative field lies in the fact that most of the power not picked up by the receiving coil remains bound to the vicinity of the sending unit, instead of being radiated into the environment and lost.” With such a design, power transfer has a limited range, and the range would be shorter for smaller-size receivers.”

The future of WiTricity is certainly enough to excite even the most moronic of us; that is to say, if it can be created in such a way that it is practical in use. In the mean time, we’ll just have to invest in sleeping pills or simply remember to plug in our cell phones.

Related:

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What does the current economic meltdown mean for Tesla

NVIDIA Tesla - the world’s first personal supercomputer unveiled

Entry was posted on Friday, June 8th, 2007 at 12:29 pm under Technology.  Print This Post

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