Let's Pull the Plug on Power Cords

Nikola Tesla first discovered wireless power back in the 1890s, and yet more than a century later we're still stuck with cumbersome cables, at the mercy of the nearest wall outlet to power up the gadgets we increasingly rely on. Thankfully, not for long: There are signs that the electronics industry is finally putting wireless charging technology to good use.

“Wireless" power can mean two things: One is inductive charging, which requires the transmitter and receiver to make physical contact; it's what charges your electric toothbrush as it sits in its tray. The other is trickier, and more exciting: wireless power based on magnetic resonance allows for a longer-range transmission, creating a sort of ambient, omnipresent charge. So theoretically you could walk into a room and your device would start magically charging from a energy being beamed down from several feet away.

Inductive chargers for mobile devices have been around for several years, but now the nascent technology is starting to take off. Samsung, Google, and Apple's smartphones and tablets all support cord-less power via cases and covers, and new gadget startups have launched similar portable chargers.

Inductive charge also powers the Powermat devices popping up in public spaces like airports and restaurants. It means that in the near future—and in some businesses already—you'll be able to set your phone down on the table next to you and it'll charge up while you're waiting for your meal.

That's still slightly more convenient than toting around a power cable, and certainly better than that panic-stricken moment when you're out and about, your smartphone dies, and you realize you’re completely lost without the internet in your pocket. But truly wireless ambient power that can charge your phone without any physical contact is the “science fiction becomes science fact” dream. That capability is considerably further into the future, but nevertheless, it’s in the works.

To wit: The Alliance for Wireless Power recently launched a device called Rezence, showcased at the Mobile World Congress in Barcelona last week. The "long-range" charger can reach a couple inches—enough to beam the power through a tabletop, so you can screw the transmitter under a table and charge a phone by just resting it on the surface. According to the MIT Technology Review, all the major players are thinking about adopting the Rezence device.

How it works, per MIT Technology Review:

In wireless charging systems, a current is passed through a coil to generate an electromagnetic field, which creates another electric current in a coil in a nearby device. But in existing devices, such as the Lumia phone, the adjacent coil has to be positioned very closely—hence the special pad. In the new version, called highly resonant technology, the sending and receiving coils are tuned to resonate at a specific frequency, allowing charging at larger distances.

The group is one of three competing industry standards whose battle to be the primary protocol has kept wireless power in a relative standstill for half a decade: the Wireless Power Consortium’s Qi standard, the Power Matters Alliance standard, which the Powermat and iPhone use, and the Alliance for Wireless Power’s A4WP standard. Last month, two of the groups merged, loosening some of the gridlock.

That might help speed along the other long-range wireless devices in the works: A company called Witricity has demonstrated prototypes with larger coils that can power electronics from about a meter away, and the startup uBeam is developing a similar wireless charging system that TechCrunch’s Michael Arrington called “the closest thing to magic I’ve seen in a long time.”

And it's not just your the cell phone charger that's on its way to becoming obsolete. Next-gen wireless power could one day be used to charge larger electronics like your computer or TV. Apple won a patent in December for a system that would use near-field magnetic resonance to charge a room full of Apple products.

It could take years, but the tangled piles of cables filling up power strips tucked behind furniture will eventually seem as antiquated as landline phones and dial-up. Wireless power, instead, could one day turn your whole house into a sort of energy field to charge the future smart home.