Witricity - cue cancer conspiracy...wait for it...wait....now

i-490b1f884db49accb1c8aa1ffe000095-tesla_coil_big.jpgI'm going to make a bold bold prediction right here on Omni Brain. With the announcement of wireless electricity there will soon be a group of crazed wackjobs protesting it (well.. that is if it ever actually makes it to the consumer level) because the electricity flowing through the air causes Cancer, Autism, Genital Warts, or something else silly. Yes yes.. you've heard it first right here on Omni Brain!

Here's some of the details from BBC News:

US researchers have successfully tested an experimental system to deliver power to devices without the need for wires.
The setup, reported in the journal Science, made a 60W light bulb glow from a distance of 2m (7ft).
WiTricity, as it is called, exploits simple physics and could be adapted to charge other devices such as laptops.

And here's a bit more in depth description from the MIT Press release:

WiTricity is based on using coupled resonant objects. Two resonant objects of the same resonant frequency tend to exchange energy efficiently, while interacting weakly with extraneous off-resonant objects. A child on a swing is a good example of this. A swing is a type of mechanical resonance, so only when the child pumps her legs at the natural frequency of the swing is she able to impart substantial energy.

Another example involves acoustic resonances: Imagine a room with 100 identical wine glasses, each filled with wine up to a different level, so they all have different resonant frequencies. If an opera singer sings a sufficiently loud single note inside the room, a glass of the corresponding frequency might accumulate sufficient energy to even explode, while not influencing the other glasses. In any system of coupled resonators there often exists a so-called "strongly coupled" regime of operation. If one ensures to operate in that regime in a given system, the energy transfer can be very efficient.

While these considerations are universal, applying to all kinds of resonances (e.g., acoustic, mechanical, electromagnetic, etc.), the MIT team focused on one particular type: magnetically coupled resonators. The team explored a system of two electromagnetic resonators coupled mostly through their magnetic fields; they were able to identify the strongly coupled regime in this system, even when the distance between them was several times larger than the sizes of the resonant objects. This way, efficient power transfer was enabled.

Magnetic coupling is particularly suitable for everyday applications because most common materials interact only very weakly with magnetic fields, so interactions with extraneous environmental objects are suppressed even further. "The fact that magnetic fields interact so weakly with biological organisms is also important for safety considerations," Kurs, a graduate student in physics, points out.

The investigated design consists of two copper coils, each a self-resonant system. One of the coils, attached to the power source, is the sending unit. Instead of irradiating the environment with electromagnetic waves, it fills the space around it with a non-radiative magnetic field oscillating at MHz frequencies. The non-radiative field mediates the power exchange with the other coil (the receiving unit), which is specially designed to resonate with the field. The resonant nature of the process ensures the strong interaction between the sending unit and the receiving unit, while the interaction with the rest of the environment is weak.


So what do you all think? Will this make it to the consumer level? And will it cause cancer? ;)

More like this

I dunno if it'll cause cancer, but I'd be a little worried worried about my hard drives, my magnetic compasses and my credit cards...

As for whether it'll make it to consumer level... Does it scale?

"So what do you all think? Will this make it to the consumer level? And will it cause cancer? ;)"

I'm going to venture: Hmmm, Possibly, and No.

Well, while we wait, why don't we compile the WiTricity wrong-end-of-the-stick bingo (or drinking game if you prefer):

Someone says that it's about electricity or electric fields - 1 point (it's about magnetic fields)

Someone uses the words 'radiation' or 'radiating' with regard to the fields - 1 point (they're non-radiative)

Someone says that this tech is dangerous based on either Panorama's recent Wi-Fi documentary, or Julia Stephenson's column in the Independent about 'electrosmog' - 3 points

Someone says "But scientists once believed the earth was flat or that asbestos was harmless, so who *knows* what this might do!!?!?!" - 5 points

Someone says that this should be banned because we *already know* that magnetic fields give us cancer/autism/what not, and refer back to a tiny case-control study of about 10 people - 6 points

Neat, but I'm not sure how practical it would be. Implementing it commerically would probably require a high degree of coordination between the devices to make sure everything gets power and nothing gets fried. Also, although only the devices which resonate at the same frequency (I'm guesing this is achieved with some form of LRC circuit) will interact with the transmitting solenoid at a distance, other objects that are close by could act like the second solenoid in a transformer, which doesn't need to operate at the same frequency - indeed, the point of a transformer is for them not to. Also, I think the solenoids need to be parallel for it to work optimally since the field only induces current when it is perpendicular to the wire. Not insurmountable problems, but solving them in a device that's affordable, reliable, and easy enough to set up for commerical usage could be tricky.

As for cancer, you'd have better odds sucking plasticizers out of the insulation on the wires.

Skinny Ralph, I won't comment on your prediction. Mind control via WiFi is already a hot topic among the conspiracy nuts.
As an Engineer I will say enough RF energy will cook meat. What it does in smaller doses is still debated but I don't think it is a good idea to fill our living space up with it.
Even if our biological systems can deal with it our sensitive electronic devices can't. This is why the FCC controls spurious emissions.

On the "invention" this is not an invention. Rank amature ham radio operators used a light bulb and coil for at least 40 years to determine resonance points in their antenna systems. The distinction between a radiating system and a "non-radiant" system is bogus. All tuned radio frequency systems radiate to some degree. Its a matter of efficiency. If you look at it at the power transmission standpoint the "non-radiant" efficency gets lower and lower as the transmitter-receiver coupling drops. The original article I read said the efficiency of the system was 45%. That means 55% of the energy is going somewhere else. Depending on how the 45% was arrived at, as much as half of the energy can be radiated into the surronding area. When the transmitter and
receiver are uncoupled as when you drop your cell phone in your pocket, the coupling efficiency goes to zero. Doh!

Anyway it is bogus to call this an invention without showing some way to achieve rf coupling efficiencies greater than 90% at a considerable distance and the resulting spurious radiation less than a few micro watts per cubic meter.

This flap is a demonstration of the weakness of the Engineering programs in major universities in the U.S. and the willingness of the media to pick up junk science.

Are you listening Ponds and Fleishman?

The only commercial application I can think of is to make items water-proof as there will be no need for a connector hole for moisture to seep through. This would be a very small distance and could be achieved when almost touching.

As for dangers, a microwave cooks stuff at 2450 MHz (wikipedia) it would be interesting to see what frequency this device operates at "magnetic field oscillating at MHz frequencies".

I agree with Russell's post.

Come on guys, give credit where credit is do! No matter how you disguise your work with fabricated theories, it is still the same experiments that Nikola Tesla and others have previously explored. Without wires, Tesla lighted a bank of 200 light bulbs that were 50 watts each from over 26 miles away during his Colorado Springs experiments in 1899! Beat that, all you nerds!


I predict that if this technology is used for power transmission on any significant commercial scale, electricity "theft" is going to become rampant.