Imagine if the next time you wanted to charge your smartphone, instead of hooking it up to a wire and plugging the cord into an electrical socket, you just turned on a charger somewhere in the room.
Soon, we probably won’t have to imagine this anymore. Companies are quickly improving new kinds of wireless charging systems that would allow the “beaming” of electrical energy up to several dozen feet across a room or space.
The Beginning of Wireless Charging
Several years ago, companies started experimenting with what's called Qi wireless charging, which works on the principle of magnetic induction (we’ll get to that later) — these types of systems are able to transfer charge from a charger to a device without using a cord, but the distances that they send energy are usually measured in centimeters. In other words, the device has to be right up against the charger for the whole thing to work.
Over time, companies like Samsung have moved from this original type of system, to new wireless charging systems that can send power across a longer distance.
Now, researchers at the vanguard of the energy industry are looking at ways to take these signals a longer way from a charger or base. For example, workers at MIT have built a system called MagMIMO that can detect a device and project a form of energy toward it. This article from Extreme Tech explains how a router can "ramp up" its signal strength toward a particular device, to basically throw electromagnetic fields farther.
Another company called UBeam is experimenting with using ultrasound to get electricity moving through the air. This New York Times article shows early prototypes for this technology feature ultrasound charging transmitters, portable chargers for devices that can be carried around the room.
“If wireless power is everywhere, then the size of your battery can shrink, because it’s always charging.” says UBeam founder Meredith Perry. “You’ll never need a cord again, and you won’t need international charging adapters.”
One of the most interesting new projects is from a company called Ossia — an article on Tom's Hardware shows how this company’s “Cota” technology plans to send wireless charging signals up to 30 feet. Using common directional beacon systems, Cota would throw out about 1 watt of energy, or possibly a bit more juice to devices that are not being worn on the body.
The company is working on changing its firmware, recalibrating its circuitry and making the process energy efficient.
Check out this video to see how that Cota’s imaginary end user “Dave” moves around without any cords or cable to charge his devices.
How It Works
What all of these projects have in common is their use of electromagnetic fields to send energy from one physical spot to another.
The original Qi system worked in the process of magnetic induction, where the transmitter and receiver had to be next to each other in order to transfer power. These new systems work on the basis of magnetic resonance — a transmitter coil in one place beams energy via electromagnetic waves to a receiver somewhere else.
These systems are very new to us, but the idea for this technology has actually been around for quite a while. Followers of Nikola Tesla, the inventor of the late 1800s, know that Tesla actually proposed this kind of precise energy transfer during his struggle with Thomas Edison and the eventual aftermath, in which traditional electrical energy systems emerged. Lots of Tesla fans contend that if we had only listened to a different voice, we could have a lot of these technologies already in place, possibly saving ourselves a lot of carbon emissions and building cleaner and more sustainable alternatives.
Health and Safety Questions with Wireless Charging
Inevitably, as we look at these systems, we will start asking how safe they are.
The answer is a little bit complex. The companies in question claim they are very close to getting full approval from the FCC and other regulators. They claim that their systems are inherently safe, because they don't exceed certain spectrums or intensities of signals.
In answering this question for readers, this Mental Floss article points out how most induction chargers generate very weak fields that shouldn't be a concern.
“As for safety,” writes James Hunt, “There's nothing to worry about.”
In fact, says Hunt, conventional cable designs are more unsafe, because we run the risk of shocking ourselves if cords become worn or frayed.
However, it's important to know that these new wireless charging technologies have not actually passed regulator tests so far. Also, their safety is likely to be debated in much the same way that traditional cell phone technologies are — these relatively new forms of energy transfer are still being looked at in different ways by different people. Safety advocates who don't feel entirely comfortable with the radio waves we already get from our smartphones cite the classification of these technologies by the World Health Organization as “possibly carcinogenic,” (due to questions about glioma and other conditions) and you'll still find a good number of cantankerous old people who will tell you that holding a cell phone to your head is like frying an egg in a frying pan.
However, it's likely that with regulator approval, new wireless charging techniques will be embraced in the same way that smartphones currently are — in other words, in for a penny, in for a pound.
Looking at how far we've already come in pioneering wireless charging, it's easy to see how the next generation of devices will work. We’ll carry them with us throughout the day, without the need to constantly be plugging them in somewhere. As a result, we’ll use them even more than we already do. Portability will keep building on itself as a value proposition, and we'll all get closer to that future world where our devices are more and more a part of us, where humans and their technologies become even more vitally interlinked, until it eventually becomes difficult to figure out where our bodies end, and where our smartphones begin.
Relax, though — we’re not quite there yet. Look for more of these technologies to start coming to markets near you so that you can finally throw away those annoying smartphone cords.