Long-Range Wireless Charging: Not Quite There Yet

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Someday soon, smartphones, portable consoles, and speakers will no longer need a cord—or a charging pad—to charge.

Research for long-range wireless charging devices powerful enough to cover entire rooms made headlines recently, and a new device that promises this kind of coverage—the MotherBox—recently made its debut on Indiegogo.

"There is an enormous pent-up consumer demand for a long-range wireless charging technology which would enable devices such as smartphones, tablets, fitness bands, and health sensors to operate continuously without having to be plugged in or placed on a charging mat every day," says Matthew Reynolds, associate professor of Electrical Engineering and Computer Science & Engineering at the University of Washington. "But long-range wireless charging has been held back by safety, efficiency, and cost."

Perfecting this technology would obviously eliminate the hassle of plugging your devices into an outlet or positioning them on a charging plate, but it could also free new technologies, such as augmented and virtual reality headsets, from a tethered existence.

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Last month, Disney Research showed off a volumetric wireless power system that can charge hundreds of devices without wires—provided you're inside a room lined with aluminum panels.

"The work presented by Disney Research is an intriguing first step because it shows the potential for very high charging efficiency, but only if users are willing to modify their living rooms with metal walls and a large copper pole in the middle" says Reynolds. "This is a great first step, but also it seems pretty far from practical for existing homes."

Efficiency, Reynolds says, goes hand-in-hand with safety, and reaching a high charging efficiency would require the majority of the energy sent by the charger to be received by the mobile device, otherwise it might be harmful to humans.

In addition to installing giant iron poles and aluminum walls, there's also the large range of devices to charge—each of which would need a custom receiver that fits the size and shape of the device. Yank Technologies's MotherBox solves this problem by using receivers with Lightning connectors, micro USB, and USB Type-C ports, and claims to cover three to four devices for up to 20 inches. The further the device is away from the MotherBox, though, the less wattage actually makes it to the phone.

"We created these dynamic networks that are based on your phone's movement," says Josh Yank, CEO of Yank Technologies, which is currently within the Columbia University Startup Lab. "The tech is really scalable; you can really do as many devices as you want depending on the size."

Along with cost, there's still the issue of safety. Yank says MotherBox runs under FCC regulations that allow for higher power levels than Wi-Fi and Bluetooth devices, which are covered by regulations for radio frequency devices and often only utilize fractions of a watt for communications signals because nothing is being heated.

"The problem is that wireless power transfer is currently a gray area in the FCC regulations," says Reynolds. "The FCC does not specifically have a legal basis for wireless power. In other words, there are no frequency bands specifically set aside for use in wireless power transfer."

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Devices that emit a lot of power have to be shielded; the MotherBox's coiled core is protected by a shell.

Yank is confident that the next iteration of the MotherBox will have more power, accomplished by using an amplifier, and could potentially charge a laptop. As of now, he's much more interested in mobile charging without cables, and is currently offering the MotherBox Mini as a first step in that direction.

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"The Mini is sort of like if an external battery pack and wireless charging had a baby," says Yank. "For people who are on the move all the time, like business professionals, the Mini would be a cable-less alternative."

The Indiegogo campaign lists the MotherBox and MotherBox Mini at $159 for both—certainly an affordable price point for many consumers. It's now fully funded and Yank expects to launch this fall, provided it does not fall prey to the crowdsourcing curse. Other companies are experimenting with this technology, too, with mixed results. True room-sized wireless charging for consumers might be a ways off, and is contingent on FCC rules in the near future.

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