On Wireless Charging

PowerKiss, a Finnish company, recently launched a line of products with small receivers that plug into handheld devices (the Ring) and an electrical transmitter built into a piece of furniture (the Heart), pictured. When a device is placed on the table it charges wirelessly by using a resonating field induction that creates an electromagnetic field around the Heart transmitter. The Ring receiver adapts the current produced by the field to the requirements of the mobile device. Induction of this kind has a short range so the transmitter and receiver must be close together.

Arthur and I, on a long London walk, once discussed whether a wireless charge would one day be possible. He noted this impossible since a charge must be transferred via a conducting path of some sort. Here is what he says about PowerKiss:

"This is a clever idea and I wonder if it will really take off. You have to convince people to buy the receiver thingie. And you have to convince furniture manufacturers to build the wires into the furniture! I think when we talked about this previously, the idea was whether you could "beam" energy around across distances and that turns out to be very difficult. Radar dishes and lasers do indeed beam energy from one place to another, but it's hard to recover the energy and use it at the other end. And a person who gets in the way suffers bad side effects like cancer or just getting burned.

What they're doing here is putting you and your electronics inside a big electric field. Maybe a little bit analogous with those wires they bury in the asphalt at intersections to detect when cars are stopped at the lights, or your electric toothbrush which charges when you put it in the stand. I'm surprised they can get enough energy into the little receiver to charge a phone. Maybe over a long period of time you can charge it.

We're not talking about a lot of energy to run a phone (as evidenced by the tiny battery).

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