“Wireless charging” features built into recent devices, like the iPhone XS, certainly make it sound like our present-day consumer tech is cordless. That’s not quite true, of course. A fancy charging pad still needs to be plugged into something — a wall outlet, say — meaning there’s a lot to trip over even after upgrading to the latest and greatest smartphones.
And so, the inevitable question arises: When will we finally ditch the wires altogether? It really depends on who you ask, and how far into the future you’re thinking.
The technology required for true wireless charging has been investigated as far back as 1890, first by inventor and scientist Nikola Tesla, who successfully transmitted power over long distances in demonstrations, but never completed his research. Tesla — the man, not the car company — actually invented many modern wireless electricity techniques almost 100 years ago, including the basis for capacitive charging today. A century later, we’re only just beginning to expand on these ideas.
Apple, with its massive market share, sent a clear signal: Wireless charging is here to stay.
The wireless charging in current phones uses a technology called “inductive coupling,” which works over very short distances. This method isn’t new, and it’s barely “wireless”: old electric toothbrushes made by Oral-B used it in the 1990s, for example.
If you have a phone that supports wireless charging today, you can hover it about a centimeter off its pad and maintain the current. But practically speaking, the device needs to rest on top of it. There’s a tight coil of copper in the charger, which generates an electromagnetic field. That field is received by another coil in the back of your phone, and then it’s converted back into electricity.
Interest in this technology surged after Apple adopted wireless charging last year for the iPhone X and iPhone 8. This caused the smartphone industry to finally settle on a wireless charging standard called Qi, which guarantees compatibility with a wide range of chargers. Qi has been around for years in various forms, with many Android phones using the technology as far back as the Palm Pre in 2009.
The addition of Qi to the iPhone led to a slew of chargers joining the market almost overnight. Apple, with its massive market share, sent a clear signal: Wireless charging is here to stay. Suddenly, Qi pads were everywhere — IKEA has even experimented with building the technology directly into its furniture.
While Qi may not be so exciting, other wireless innovations show promise, and aren’t actually that far away.
Resonant inductive coupling, which shares many similarities with inductive coupling, has one side of the copper coil “resonate” or vibrate, resulting in the ability to send power over much higher distances in much higher voltages. Others use different ideas, such as radio frequencies (RF) to transmit over longer distances, like Energous’s WattUp, which touts a theoretical 15-foot range.
Researchers are actively working on these ideas, with some demonstrations, at scale, already available. Disney in 2017 showed off a “living room” prototype that can power 10 devices wirelessly, including an iPhone, a lamp, and other objects. The idea, in the long term, is to hide a bunch of coils in your walls and forget wires entirely. But today, there’s a catch: Disney asks that you don’t stand within 46 centimeters of the giant copper pole in the middle of the room, as it exceeds federal guidelines relating to human energy exposure.
Stephen R. Rizzone, president and CEO of Energous Corporation, told Medium that the company seeks a more convenient future, “where electronic devices are continually ‘topped off’ versus the current need to monitor electronic devices and actively seek out a charging source to recharge.”
Another company, Cota, promises a charging experience similar to Wi-Fi: just install a transmitter and compatible devices will be powered when in range. The company is also working on a “forever battery” that will fit into old devices — gadgets that take AA batteries, for example — to make its wireless technology backwards compatible.
Meanwhile, one of the largest barriers for these types of products is safety and regulation.
On one hand, wireless charging actually reduces electric shock risk, because open wall outlets would no longer be necessary — a kid couldn’t put a fork through a wall and into the copper coils beyond. On the other hand, there’s a large unknown relating to the safety of magnetic fields and the human body. WiTricity, another startup in the space, claims the risks are no higher than with any other wireless technology (though, of course, it would say that).
True wireless is on the horizon, and we can look to electric cars for hints today.
There’s also the issue of miniaturization. It’s one thing to put a big charging coil in your phone, but how about lightbulbs, sound bars, or even a laptop? As devices get thinner, will we still be able to fit this kind of technology inside? Looking further out, questions remain around whether or not it’s possible to beam enough electricity to power a TV, computer, and a bunch of phones at the same time.
Rizzone believes it will happen.
“The ability to walk from your kitchen through the family room and into your bedroom continually charging your smartphone with safe wireless charging power — this reality is closer than you think,” he said.
He’s right that true wireless is on the horizon, and we can look to electric cars for hints today. WiTricity, which started with a focus on consumer applications but recently pivoted to wireless car charging, already has its products out in the world. Just drive your electric car over the company’s charging mat to fill the battery to full capacity overnight.
By the end of next decade, it’s likely many of us will experience wireless power at home or at the office, as it becomes the new standard and changes the way we think about wires. The death of cables has been long and painful, but it’s genuinely on the horizon, for the first time.