Electronics

Disney Research turns a whole room into a wireless charger

Disney Research turns a whole ...
Researchers custom built a room with metallic surfaces to enable free-range wireless transfer using Quasistatic Cavity Resonance 
Researchers custom built a room with metallic surfaces to enable free-range wireless transfer using Quasistatic Cavity Resonance 
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Researchers custom built a room with metallic surfaces to enable free-range wireless transfer using Quasistatic Cavity Resonance 
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Researchers custom built a room with metallic surfaces to enable free-range wireless transfer using Quasistatic Cavity Resonance 
Devices can be charged regardless of their orientation in the room thanks to a new receiver design
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Devices can be charged regardless of their orientation in the room thanks to a new receiver design
Scientist Matt Chabalko powers up an LED light in the room
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Scientist Matt Chabalko powers up an LED light in the room
The setup outside the room 
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The setup outside the room 
The setup inside the room
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The setup inside the room

While there's been no shortage of attempts to incorporate wireless power transmission technology into our furniture, garages and living rooms, reality has not quite caught up with the futuristic ideals of untethered wireless freedom. That said, we might be inching closer to it with Disney Research's recent demonstration of a new method for wireless power transmission that could charge your devices automatically the moment you walk into a room, making electrical cords and charging cradles a thing of the past.

At present, wireless charging is stymied by two challenges: range and health concerns. Despite their reach, radiative transfer methods, which are used for radio communication, have not found much favor elsewhere due to health and safety concerns. On the other hand, while safe, non-radiative methods such as near-field coupling are highly localized and require the devices to be placed near the charging source.

To circumvent these limitations, Disney Research scientists, led by associate lab director and principal research scientist Alanson Sample, turned to a method called Quasistatic Cavity Resonance (QSCR), which induces electrical currents in an enclosed metallic structure. For the purposes of this proof-of-concept, the researchers constructed a 16-by-16-foot room with aluminum walls, ceiling and floor bolted to an aluminum frame. A copper pole, with a small gap into which discrete capacitors were inserted, was placed in the center of the room.

The setup outside the room 
The setup outside the room 

A signal generator located outside the room produces a 1.32 MHz tone, which is given a boost by a power amplifier. A coil receiver then connects this signal to the capacitors in the pole and this system enables power to be transmitted to receiving coils that operate at the same resonant frequency as the magnetic fields. By channeling the induced currents that flow through the walls, ceiling and floor in the room, the capacitors set the electromagnetic frequency of the structure and confine the electric fields, isolating potentially harmful electrical fields at the same time.

On a separate note, because of the way the magnetic fields swirl around the pole, the device has to be situated perpendicularly or orthogonally to the magnetic fields to receive power. If the receiver coil is parallel to the plane, it receives no power, which defeats the idea behind this project since the point is to enable people to charge their devices anywhere in the room. To get around this issue, the researchers came up with a receiver design with three orthogonal coils so at least one of them would be able to receive power regardless of where it's located.

"This new innovative method will make it possible for electrical power to become as ubiquitous as Wi-Fi," says Sample, adding that it could in turn "enable new applications for robots and other small mobile devices by eliminating the need to replace batteries and wires for charging."

The setup inside the room
The setup inside the room

Though the room had to be custom-built for this study, Sample believes the need for such metallic surfaces will be significantly reduced once the QSCR technology is optimized. Building owners will then be able to retrofit existing structures via modular panels or conductive paint, and in the case of larger spaces, by inserting multiple copper poles.

One advantage this method is said to offer is that since the coupled resonators only share energy with devices of the same resonant frequency, these low megahertz frequency magnetic waves have little effect on common everyday materials – unlike low frequency inductive systems that result in eddy current heating – thus allowing for home and office furnishing to be included in the room. In addition, the high Q-factor and sub-wavelength operation of the QSCR room allows for the inclusion of windows and doors without any significant impact on system performance.

Scientist Matt Chabalko powers up an LED light in the room
Scientist Matt Chabalko powers up an LED light in the room

Now for the 64,000 dollar question: will being in this room fry your brain? While the researchers ensured the study was conducted according to Federal safety guidelines, there are a few things worth pointing out. First, there is a limit to the amount of power you can pump into the room. As the authors note in their study, while it is possible to safely transmit 1.9 kilowatts of power to a receiver at 90 percent efficiency (the equivalent of charging 320 devices), due to the amount of unused power stored in the room, the appliances in the space would have to use and receive that much power.

Secondly, while around 100 watts of power can be transmitted into the room safely, there would need to be a significant amount of utility taking place. For larger amounts, standard methods such as real-time power tracking can be used to ensure safe operation. Finally, as per SAR (specific absorption rate) requirements, safety strategies such as intrusion detection or a decorative wall would need to be employed to ensure that people do not venture within 46 cm of the pole.

Though work on this project is still in its nascent stage, the researchers believe this form of wireless power has the potential to eliminate the need for wires and batteries by enabling users to charge their devices simply by walking into a QSCR-enabled space, thus allowing an unprecedented amount of spatial charging freedom. One interesting advantage it has over other solutions we've covered is that it can be scaled to size, depending on the application. The researchers did not mention what plans Disney has for this technology but one can imagine how it can be used in its theme parks, for starters.

"In this work, we've demonstrated room-scale wireless power, but there's no reason we couldn't scale this down to the size of a toy chest or up to the size of a warehouse," concludes Sample.

Watch the video below to see how QSCR-enabled wireless power transmission works.

The study was published in PLOS One.

Source: Disney Research

Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer - Tech Video

8 comments
PatrickSavageStarThompson
Stripper powered "research".
zr2s10
I think full rooms aren't going to happen on a mass scale, due to cost. But converting coffee tables, desks, etc, to be able to charge anywhere on their surface would be great.
tjcoop3
One word Tesla. The man not the company that makes crappy electric cars at a high premium!
Grainpaw
What will this do to a pacemaker/defibrillator implant?
FabianLamaestra
Cancer much?
Scottsdale Bob
The problem has been solved by Witricity with no human exposure problems. They have a complete house operating with TVs, Stereos, Lighting, PCs, Drones and charging electric cars. Go to www.witricity.com
ljaques
Yeah, why not flood our bodies with yet another RF wave, since it's easier to do than walking three feet and setting it down on a charger? Lazy much? SmartMeters already follow regulations but can transmit 160x the max dose while following those regs. Safe? Not even. Charging pads would make things easier while not endangering human (or pet) lives. == I came home from vacation last year and was mowing the lawn a few weeks later when I spied a brand new item on the side of my house. They had replaced the gas meter and hadn't bothered to tell me. I hadn't been sleeping well since returning from CA, so I thought that might be the cause. Sure enough, after putting a piece of aluminum screen in an L shape around the meter and grounding it, I started sleeping longer. I called the gas company and asked 4 questions: 1) why hadn't I been notified, either before or after? 2) why was it replaced? 3) what was the power level? and 4) how far away could they read the meter? They apologized for not notifying me and said it had been replaced because "The battery needed replacement." I mentioned the difference between a $700 meter and a $4 battery but she didn't know anything more. <g> She said they'd have to call back with the power level and meter reading distance. When they called back, they said "Oh, it's a safe meter. The old ones could only be read for a couple blocks. These can be read for over a mile." Since the deed was already done, I shrugged and instantly shielded myself and house from it, JIC. But now I know, from personal experience, that the scare over SmartMeters isn't just fear and imagination, and this wasn't even a hot meter. I then called the electric company and made sure that they had a note on my account telling them "Never install a SmartMeter on my house."
JanoriaCorven
Quasistatic Cavity Resonance (QSCR) look it up. its not an RF transfer. not in the least. and 1.32mhz? is not enough to harm. do research before putting your tin foil hats on!