Taking the lead

Posted on 13 Sep 2007 at 16:27

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Given that the science behind WiTricity is not entirely new, we asked Aristeidis Karalis, one of the team working on it, why he thought nobody had attempted such a system before. He told us it was a case of motivation: "Ten years ago, a wireless power transfer technology would be completely useless. There were no portable electronic devices whatsoever." That may not be entirely true, but there has certainly been a massive increase in portable devices since then.

WiTricity is in early development, and the team doesn't yet have an industry partner for turning it into a commercial product. Karalis told us that among the issues to be addressed on the way from science to product are the full system design and packaging. "Hopefully, this should take three to five years. The device coil must be small enough to fit into the device of interest. The source does not have to be small, as it can be placed on the ceiling or under the floor. The goal is to address the average consumer and make this accessible to the home."

Powering forwards

While Tesla developed many of the technologies involved in wireless power transmission, he struggled to secure funding for his ambitions and was never able to bring them to widespread commercial use. For a century, we've continued to rely on wires to transmit power, with only very limited use of niche wireless applications.

Now, though, the need to power an increasing number of gadgets and to cut down the rising number of power adaptors has made wireless power an attractive proposition. Technologies such as Powercast and eCoupled use well-established technologies in a new way, and seem poised to propel wireless power into the mainstream. Of all the technologies we've seen here, Powercast's radio system has the longest potential range, but safety dictates that it must also use the lowest power level. As such, it may prove to be a niche consumer product, but it's ideal for many industrial applications.

Induction mats, on the other hand, have the potential to free us from the array of AC adaptors that loiter behind a typical computer desk. Though they have the shortest range, they can transfer high amounts of power, making them a feasible way of charging everything from phones to electric cars, and also for directly powering toasters and kettles.

MIT's WiTricity technology is the furthest away from becoming a commercial product, but its reasonable range and moderate power capacity make it perhaps the most exciting of the three. If the team can develop it successfully, coils built into the buildings where we live and work could provide our electrical devices with continuous power.

For each of the technologies, however, there remain some significant hurdles. With the world's growing rate of energy consumption and our increasing concerns about conserving energy, future wireless technologies will hopefully be judged as much by their efficiency as by their convenience. Meanwhile, convenience isn't just about design. The consumer electronics industry is massive, and for any single company to make its product as commonplace as the mains socket is an enormous challenge. Let's hope it's not too long before the best design meets that challenge.

Author: Simon Handby