Katie Hall was shocked the second she saw it: a light-bulb glowing in middle of a room with no wires attached.
Looking back, it was a crude experiment, she remembers: a tiny room filled with gigantic cooper refrigerator coils — the kind you’d see if you cracked open the back of your freezer.
She walked in and out between the coils and the bulb — and still the bulb glowed.
“I said: ‘Let’s work on this. This is the future.’”
What’s the trick?
“We’re going to transfer power without any kind of wires,” says Dr Hall, now Chief Technology Officer at WiTricity — a start-up developing wireless “resonance” technology.
“But, we’re not actually putting electricity in the air. What we’re doing is putting a magnetic field in the air.”
It works like this: WiTricity build a “Source Resonator” — a coil of electrical wire that generates a magnetic field when power is attached.
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If another coil is brought close, an electrical charge can be generated in it. No wires required.
“When you bring a device into that magnetic field, it induces a current in the device, and by that you’re able to transfer power,” explains Dr Hall.
And like that, the bulb lights up.
Don’t worry about getting zapped: Hall assures that the magnetic fields used to transfer energy are “perfectly safe” — in fact, they are the same kind of fields used in Wi-Fi routers.
In the house of the future, wire-free energy transfer could be as easy as wireless internet.
If all goes to WiTricity’s plans, smartphones will charge in your pocket as you wander around, televisions will flicker with no wires attached, and electric cars will refuel while sitting on the driveway.