Is Wireless Power Closer Than We Think?
Tesla Would Be Proud
A few years back, Marin Soljačić was driven from bed by the insistent beeping of his mobile phone. But it wasn’t beeping for him to answer it, it was beeping for him to plug it in. Since that night, the assistant professor of physics at MIT, has been thinking about ways to start his phone charging as soon as he enters his home - without the need for plugs or wires.Jennifer Chu at Technology Review writes that Soljačić considered using radio waves, but found that most of their energy would be lost in transmission. Targeted methods like lasers require a clear line-of-sight and could be dangerous for anything in their way. According to Chu, he eventually settled on a phenomenon called magnetic resonance coupling, in which two objects tuned to the same frequency exchange energy strongly but interact only weakly with other objects.
“A classic example is a set of wine glasses, each filled to a different level so that it vibrates at a different sound frequency. If a singer hits a pitch that matches the frequency of one glass, the glass might absorb so much acoustic energy that it will shatter; the other glasses remain unaffected.”
Now, Soljačić and his team have successfully demonstrated the use of magnetic resonance coupling to power a 60 watt light bulb from a distance of roughly two meters - and through a thin wall.
The most effective setup, thus far, transfers power over a distance of two meters with about 50 percent efficiency. The team is looking at other materials to decrease coil size and boost efficiency. “While ideally it would be nice to have efficiencies at 100 percent,” says Soljačić. “So realistically, 70 to 80 percent could be possible for a typical application.”
While some wireless power technologies have emerged in the marketplace, Soljačić’s technique differs in that it might one day enable devices to recharge automatically, whenever they come within range of a wireless transmitter.
Tesla did this already. Its nothing new.
For the sort of distances relevant to medical devices the technology already exists. It’s normally quite easy as medical devices don’t tend to be high powered and RF isn’t damaging to the body. The difficulty is keeping efficiency over any distance. Check out the similar article and references at.
http://www.edn.com/article/CA6455599.html
Cool, yes, but only suitable for special (though perhaps important) applications. I’m not sure what theses applications would be, though Michelle B. has indicated some good ones. Otherwise, I agree with Matthew D.- the efficiency is going to be low, so that tempers my enthusiasm.
it would be very lazy to not plug in your phone, thinking about the technology i really doubt you could get 100% efficiency but if so it would be a breakthrough. i agree with Matthew Davidson about energy resources. But charging medical implants seems a very cool idea.
An interesting idea to be sure. If the possibility exists to boost efficiency to a usable level, cell phone charging is only the beginning. Imagine of the batteries of electric cars were all tuned to a specific frequency, the implementation of a city-wide or country-wide power grid could mean that cars would never be required to fill up on gas. Not to mention such an implementation could power traffic lights, public transportation systems, and other municipal services. I’d be interested in seeing plans for large-scale deployment of this technology.
Although wires will probably never be totally replaced i see tremendous possibility for this technology and efficiency will go up with research and fine tuning. Basically any application where providing power was a major hurdle in the design now has a solution. plus this is a huge leap compared to previous technologies
Yeah, like I want still more energy broadcast into my body and brain.
Silly me. Fortunately, we already know the industry that develops around the new technology will swear that it’s totally safe, and government will decide not to regulate it because there’s no “proof” it might be harmful.
Hey, profits come first. After all, corporate products and services are innocent until proven guilty … unknown decades and countless deaths later.
Thank you, doc, but I’ll just continue to plug in my cellphone and computer. Really, it’s not all that challenging.
The technology is still being developed. Everything starts off with a low efficiency until further research and testing can be done to increase it. Give it time and it will probably be a viable way to transmit power.
Yes, but what about all the RF interference and EMF (Electro Motive Force) interference and the effect of these not only on humans but also other gadgets (including pacemakers and the like).
In order for any such device to actually charge something, the force will have to be extremely strong for those distances.
You have toothbrushes today that charge this way, but the distance is a few millimeters and their efficiency is less than 60%. That is they consume more power than is actually used.
in the future I can see a way to transfer energy from home to home like a mesh via wireless and in turn be able to remove all them damn power poles that litter our communities.