Saturday, September 5, 2009

Good Vibrations

We've moved! Visit us at

In one of the coolest talks I've seen on TED recently, MIT researcher Eric Giler brings a metal structure resembling an empty picture frame on the stage along with an unplugged LCD TV. The crowd quiets in anticipation as he flips a switch to power the metal device. He nervously admits that it takes time to charge up. Finally, in a roar of applause, the television blinks to life.

This is the first demonstration of wireless electricity that I've ever seen. Actually no, that's a lie - my electric toothbrush works on the very same principle, although I didn't know it until I watched this video. This device however, is large enough that it can power common household electronics.

This idea of electricity without wires harks back to the first designs by Nikola Tesla - he believed, in fact, that the world would not use electricity if there were cumbersome cables involved. The problem was he couldn’t induce an electric current across large distances. His famous Tesla coils could create a massive amount of volts but only in close proximity.

This new design uses a phenomenon called resonance energy transfer. Resonance occurs when two objects vibrate at the exact same frequency, and become linked in their mutual vibration. This linkage can occur over very large distances. A common example is the opera singer who shatters a glass across an auditorium.

Wireless electricity (WiTricity) works in a similar way. It converts an electric current in the device to a magnetic field of a very particular frequency. A conversion box attached to your household electronics is tuned to that exact frequency, and when it picks up signals from the WiTricity device, it converts them back into an electric current. This technology is perfectly safe - we are already exposed to magnetic fields every moment of every day.

As the presenter points out, imagine driving your electric car into your garage where there is a WiTricity device embedded into the floor - no plugs or effort required. Or - what excites me the most, sadly - finally getting rid of the mess of cables under your computer desk! Its on the way, folks, believe it or not.

~Rheanna Sand

1 comment:

  1. Loved this talk. You could see how nervous he was when the inductor on the tv was taking longer than it should have.
    I love living in the future.