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Seattle Times staff columnist
Free high-def TV is just one benefit of Friday's shift to digital broadcasting.
A bonus may be free electricity for everyone — a tiny bit, but perhaps enough to charge small electronic gadgets and cellphones someday. Scientists at Intel's University of Washington lab are already "harvesting" this power supply in the sky.
Intel researcher Joshua Smith and UW graduate student Alanson Sample are doing it with a cheap TV antenna pointed across Interstate 5 toward KING-TV's tower on Queen Anne. If it's pointed in the right direction, it draws enough power to replace the batteries in an LED thermometer from RadioShack.
It's a simple rig, but it shows there's enough unused energy floating around to power all sorts of devices without degrading the TV signals at all.
"That's the thing with these broadcast mechanisms — if you don't collect the power and do something with it, that energy's just going to, you know, heat up the grass or something," Smith said. "There's nothing else that could happen with it."
Within three or four years, this technology could be used to direct power into phones and laptops so they could remain on standby indefinitely, without plugging into an outlet.
It may never be enough to do away with plug-in chargers, but it could supplement chargers or solar-charging systems that work only in the daytime.
The technology could also someday help Intel get its chips into a greater share of tomorrow's phones.
Smith and Sample first demonstrated their TV power-harvesting experiment in February.
More attention to the concept of harvesting wild electricity came last week when a Nokia researcher told Technology Review that he's working on a prototype phone that will draw power emitted by cell networks, TV towers and other sources.
They sound like electronic wildcatters, probing the environment for overlooked and untapped pockets of energy.
But Smith is focused more on transmission than prospecting, finding ways to get electricity to devices without wires.
Power through the air
It's a new frontier, to make wireless gadgets truly wireless.
Smith actually has been working on this for years, driven largely by his interest in robotics. The 40-year-old New York native started tinkering as a baby, when his father built a busy box with lights and switches for him to fiddle with instead of the locks in their home. Over time the box became more complicated, with boards and wires, until it resembled some of the equipment he now uses at Intel's lab, a few blocks off the UW campus.
Help robots find tools
In 2004 Smith figured out how to draw power from UHF frequencies so electricity could be passed wirelessly to RFID sensor chips. It has all sorts of industrial applications, but Smith was thinking about robots activating sensors — so a domestic robot could more easily find and use a tool with an RFID sticker, for instance.
A recent incarnation of that project wirelessly powers a device with an accelerometer, similar to those in Wii controllers.
The idea is that a controller or a computer mouse could be powered wirelessly from a transmitter without batteries. So far it works accurately within about 10 feet of the power source.
"A mouse should be relatively easy to do," Smith said. "The Wii controller, it might be a couple more years to do it, but I think it's very plausible."
Smith also collaborated with researchers at Massachusetts Institute of Technology (one of his alma maters, along with Williams College and Cambridge University) after they developed a similar approach to power a light bulb in 2006.
"A pretty big change"
"We were playing in the 1 milliwatt range, the microwatt range," Smith recalled. "Somebody comes along and starts talking 50 watts — a million times larger. It's a pretty big change, pretty interesting."
That led to Smith and his team wirelessly lighting a bulb last fall, using smaller coils than the MIT project.
More's in store, but Smith's already been dubbed in Intel's new ad campaign as one of the company's "rock-star" inventors. He's mentioned in the Chinese version, in which the Mandarin copywriters described his work as "converting air to electric energy."
Can't wait for that one.
Source: The Seattle Times
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