— Imagine a world where you don’t have to plug in
your smartphone, tablet or laptop, or even lay it on one
of the Duracell charging mats that Starbucks is rolling
out nationwide. Instead, your refrigerator sends them
power from across the room via a WiFi-like radio signal.
forget that for a while — though it might happen
Corp., a Silicon Valley startup, won awards in Las Vegas
at the recent International Consumer Electronics Show
for its WattUp system of "wire-free charging of
multiple devices at up to 15 feet." At least one
other company, Texas’ DK Tek Innovations, made similar
claims at the show.
efforts are still in the development phase, part of a
global race for what is expected to be a
a different kind of wireless charging at a distance,
less likely to stir safety concerns and face regulatory
friction, finally seems on the cusp of
Corp., of Watertown, Mass., hasn’t drawn quite as much
buzz as Energous, which went public last year. It has,
however, been quietly pursuing a wire-free concept
described eight years ago by researchers at the
Massachusetts Institute of Technology, and has announced
partnerships with major manufacturers such as Toyota and
says its technology — which does not rely on radio
waves to transmit power — has been shown to transfer
electricity with little loss to a device nearly a foot
away, even through solid materials such as a garage
floor or kitchen countertop. Longer distances are
charging is one of those technologies that always seems
to be on the horizon. Nearly three years ago, a former
chief executive predicted that WiTricity’s system
would be in consumer products by the end of 2012. That
didn’t quite happen, though the company did offer
product developers an iPhone 5 charging system last
and the wireless-energy industry continue to make
strides. WiTricity vice president Kaynam Hedayat said he
expects Intel products using the company’s system
"to hit the market by the middle of this
is expected to offer wireless charging by fall 2016 on
its plug-in Prius hybrid. And WiTricity is working with
Thoratec Corp. to develop a heart pump that will work
without wires running into a patient’s abdomen.
does WiTricity’s system — called "magnetic
resonance wireless power transfer" — work?
Hedayat likens it to the curious phenomenon,
occasionally seen as a gag in a movie or commercial,
where an opera singer breaks a glass by hitting a
can do that by generating voice at the same frequency
the wine glass resonates at," Hedayat says. A
similar kind of resonance can be used to transfer power
from one magnetic field to another, he says, without
generating electromagnetic waves like those sent by
radio or Wi-Fi devices.
"secret sauce," as Hedayat puts it, is that
both the source and the target device are equipped with
magnetic resonators — coils with electronics — tuned
to resonate at the same frequency.
says WiTricity already has 94 patents, with more than
200 others pending. And he touts the technology’s
advantages over induction charging, which often requires
a device to be in the exact right position on a mat, as
well as radio-frequency transmission, which he says
suffers from inefficiency and "is very limited by
human safety factors."
WiTricity, he says, a user will simply have to park a
car over the source, or lay mobile devices on a counter.
don’t have to think about it," he says.
wireless charging finally ready for prime time? If so,
this is another kind of cord consumers will happily cut.