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.
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May 2nd, 2008 at 4:11 pm
While an interesting idea for the future, we are currently experiencing massive worldwide upheaval and fighting for energy resources; why work on a technology that promises to be *less* efficient than what we have now?
May 2nd, 2008 at 5:57 pm
70-80% efficiency sounds pretty horrible. Also, you would need to shield your environment somehow, in order to keep your neighbors from suckling on your wireless power source.
May 2nd, 2008 at 6:24 pm
One of the seven signs of bogus technology is that the inventor pitches the technology directly to the media rather than peer reviewed journals.
Thats what we have here. The guy is a charlatan.
May 2nd, 2008 at 6:51 pm
The other %50 of the energy goes to your brain to grow tumors.
May 2nd, 2008 at 6:53 pm
Great, no expensive wires etc., Their must be many medical applications that can be implemented or improved by research in this area. Efficiency may go up with study, but right now, who knows!
May 2nd, 2008 at 6:56 pm
Hmm, interesting idea there. Did Tesla already come up with a way for transmitting energy wirelessly though?
May 2nd, 2008 at 7:45 pm
It is interesting, but possibly irresponsible to develop. As the second comment says people, including me, would flock to it. It’s true efficiency may go up. However, I would imagine radiative and dielectric loses would cripple in a normal location. That being said you can’t stop development so it will probably happen anyway.
May 3rd, 2008 at 3:53 am
In response to Matthew: While this technology is indeed inefficient for charging cell phones, that is not the goal. The ability to transport power wirelessly has a unmeasured potential for the future independence of energy as well as the ability to do what today would seem impossible.
Imagine a world where you could put a power plant next to the sun and beam the energy back to earth. Or being able to travel across the solar system without having to carry your fuel with you.
The possibilities for this technology are as endless as they are vital.
May 3rd, 2008 at 1:22 pm
What a cool idea! I think I’ve heard of certain medical implants that could recharge with radio waves… but I don’t remember if they’re in use. This would be great for people with pace-makers or inner-ear implants to help them hear.
May 3rd, 2008 at 2:53 pm
Is wireless power closer than we think? | nerdd.net…
\r\nA few years back, Marin Solja??i?? was driven from bed by the insistent beeping of his mobile ph…
May 3rd, 2008 at 3:33 pm
Tesla did this already. Its nothing new.
May 3rd, 2008 at 4:24 pm
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
May 3rd, 2008 at 5:59 pm
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.
May 3rd, 2008 at 11:04 pm
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.
May 3rd, 2008 at 11:16 pm
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.
May 3rd, 2008 at 11:18 pm
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
May 3rd, 2008 at 11:30 pm
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.
May 3rd, 2008 at 11:31 pm
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.
May 3rd, 2008 at 11:32 pm
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.
May 3rd, 2008 at 11:34 pm
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.
May 3rd, 2008 at 11:47 pm
Since 802.11b came onto the scene (popularly in … say, 2001/2002) I’ve always been astonished that we haven’t yet figured out wireless powering.
The less wires in my world, the better. I think this idea – embryonic, but great. I’m excited to watch it progress and fully anticipate seeing consumer-ready implementations in a few years (say, hopefully, by 2015 mainstream?)
Not concerned about energy efficency. Charge a price-premium to compensate for the differential and reinvest a portion of the profits. Markets can handle this efficiently – don’t know why people don’t understand econ 101. You’ll STILL scoop up a great bunch of $$$ from early adopters … probably like myself!
Danjuyo
May 3rd, 2008 at 11:51 pm
The only thing stopping us from efficient energy sources is fear. Nuclear power plants are the best source of energy we have invented and there’s no reason they shouldn’t be providing 100% of limitless energy needs. Fear.
May 4th, 2008 at 12:10 am
A remarkable invention, but nothing new, here is the original patent: http://www.google.com/patents?id=CLJIAAAAEBAJ&pg=PA9&dq=tesla&source=gbs_selected_pages&cad=0_1
I think it would be cool if they could find a way to use nano technology to improve the applications and efficiencies.
May 4th, 2008 at 12:18 am
Don’t get your hopes up yet. The RF field strengths required for this technology to work far exceed OSHA and CE limits for human RF field exposure. Further, it will wipe out nearby AM, FM and terrestrial TV broadcast receivers. This technology will be nothing more than a laboratory curiousity.
May 4th, 2008 at 12:20 am
Obviously as an emerging tech, we’re going to be seeing low efficiencies at introduction. I think that its definitely worthwhile to develop this for various applications in the future. Especially if you consider it as an optional feature in devices, as long as users are willing to pay extra (say 20 – 30% more once the idea is optimized) for that wireless convenience, which they will be if past trends are any indication. Honestly, i wouldn’t mind paying an extra 30% on my energy bill for that.
May 4th, 2008 at 12:23 am
That would be nice, no more wires and cables, hopefully the last thing this technology should do is to power/charge a cellphone.
May 4th, 2008 at 12:42 am
Let’s take this to an extreme possibility and then see what your reaction is.
How about satellites sending a certain frequency down to earth which will light up light bulbs, or recharge cell phones for the poor in Africa who have no access to electricity lines?
(solar cell power has less efficiency)
Or larger scale: Satellites sending a certain frequency down to a power station which then send out electricity on the current established lines.
More extreme: no electrical lines, no electric bricks, no wall warts, and all products have a PhD (Push here Dummy).
May 4th, 2008 at 1:23 am
I had the general concept of wireless energy a few years back when I was merely a child. I’m pissed. I should have been been smarter at the time… coulda made me wealthy.
May 4th, 2008 at 1:51 am
to all the people who thing that this is inefficient chew on this what if “they” had solar fields in space that would operate 24/7 and send the power to earth wirelessly than you would solve any power crises. even if your at 80%
May 4th, 2008 at 1:56 am
Wait so people here are saying “oh 80 percent isn’t good enough why even bother?”
come on are we so close minded that we aren’t even interested in investigating new emergent technology because we can’t see an application for them at day one, or just because by their stats they don’t sound perfect. Imagine if the Wright brothers saw they’d never get off the ground for more than a couple minutes, or Benjamin Franklin realized he’d never have a hot tub, so all of them went and instead of investigating their thoughts just went on the internet and just bitched about how their idea wouldn’t work?
God people always piss me off with their negativity. Rather than get interested in a new idea they immediately try to shoot it down.
May 4th, 2008 at 3:20 am
@Matthew & Arman
Your average light bulb is horribly inefficient. Most of the energy a light bulb consumes is dissipated as heat, not light. Anything in the 80% range isn’t bad. When the guy was saying we could get it to 70-80%, I thought he was bragging!
May 4th, 2008 at 3:35 am
Isn’t that what a PV does ?
May 4th, 2008 at 3:57 am
@P Bartlett: He’s published. Drawing conclusions without research is probably more dangerous to the integrity of research ehh?
http://www.mit.edu/~soljacic/wireless-power_AoP.pdf
May 4th, 2008 at 4:10 am
I’ve heard about this before, but this method is something I don’t remember hearing previously.
Until efficiency reaches a higher level, this seems like a great waste of resources.
I would hate to have a filling that just happened to have the same resonance frequency as a light bulb. Electrocuted without even touching a wire. But there are some really great implications for its use in the medical fields.
May 4th, 2008 at 4:19 am
Similar thing already being done here:
http://www.ecoupled.com
May 4th, 2008 at 4:28 am
“One of the seven signs of bogus technology is that the inventor pitches the technology directly to the media rather than peer reviewed journals.
Thats what we have here. The guy is a charlatan.”
Oh really? So, this professor at MIT who has a PhD from Princeton is a charlatan?
He’s part of a research team at MIT who are developing this technology.
Oh, and they did actually publish an article in a peer-reviewed journal (That prestigious one called Science)
May 4th, 2008 at 5:00 am
yes this is how my pacemaker recharges
May 4th, 2008 at 5:26 am
yea.. problem is the human body has lots of things inside it that can be affected by the similar frequency..
yay tumor..
May 4th, 2008 at 5:59 am
I am not happy with all those wires arround me…. (PC at least 3 power wires [monitor, pc and speakers], GSM charger, TV, sound system, digital clocks, not to mention the power wires in the wall)… and all of this wires emit some radiations (electro magnetic)… then we have some wireless gadgets like radio transistors, gsms, bluetooth devices, wireless modems, mouses and keyboards, TV remotes and many others…. most of them are working on radio waves, microwaves…. ISN’T THIS ENOUGH? Our homes are polluted with electromagnetic radiations!!! And we want even more???
Maybe one gadget like GSM or digital clock is not hurting us, but so many at a time???? + now the desire of even more???
They should concentrate of inventing a no emission power source battery or maybe improving the wire coating or something. I am really pro improvements…. but in my opinion there are many ways to achieve them and we certainly don’t have the necessity pick the “stupid” one
May 4th, 2008 at 6:40 am
Why the negativity? when was the last time you invented something for humanity? lol.. It’s a start! As a musician I despise cables (and adapters)! I hope I’ll still be alive when wireless power would be possible!
May 4th, 2008 at 7:04 am
I think it’s a new technology and it has a lot of promise I for one think it would be awesome if I could just walk into my house and have my ipod and cell charge. Sure it’s not ready for mainstream yet but neither were computer when they first came out, or cell phones.
May 4th, 2008 at 7:40 am
@Uncle B> I didn’t see any interest to a technique with a loss of energy of one third or one fourth, so thanks for citing medical applications (medical devices)! Obviously, there are cases where you don’t want wires going through … the skin. Could be better suited than Foucault currents in some applications.
@Tyler “put a power plant next to the sun”> huh? Why not use *directly* the tremendous energy coming from the sun? If you really want a satellite, you’d better put it in geostationary orbit, providing energy at night (it’d be lit 24/24 7/7 and it’d be “there” night’n'day). You could even have energy near the poles during the 6 months night, though it’d be difficult to point at the horizon. And there’d be a huge barrier: the atmosphere. Last problem: the size of the thing. Human needs in energy are currently pretty huge, how could you imagine a satellite providing alone the same energy as dozens of (nuclear, gaz, coal) plants? Focused on a city or an entire hemisphere without warming the atmosphere? Mmh I think solar panels or solar heaters’ll be more convenient for now
May 4th, 2008 at 11:46 am
How is this clean? Suck up some power from the grid or elsewhere *then* throw away 30% of it?
May 4th, 2008 at 11:52 am
@Shane–If you’re willing to pay 30% extra on your power bill for this (ie, use 30% more power in the process of going wireless), why do you care about “green” technology?
May 4th, 2008 at 12:48 pm
Fantastic, kepp your rechargeable applicance with you every time you go to visit a fiend
May 4th, 2008 at 3:52 pm
Tesla’s fascination with wireless power was actually his downfall. He had invented radio (Marconi’s “invention” used 17 Tesla patents), and secured funding from JP Morgan to develop a global radio network, but when Morgan found out that Tesla’s main desire was wireless transmission of electric power, funding was withdrawn and Tesla spent the rest of his life a pauper.
Why? If you transmit energy wirelessly, there is no way to bill users. And with the inefficiency inherent in a wireless transmission method, much more power would have to be produced than what was actually used.
Electric toothbrush “wireless” chargers are nothing earth-shattering; it’s a simple transformer using magnetic induction. Move the handle away from the base even a bit, and the charging stops.
Remember, Tesla’s transmitters were MASSIVE and pre-dated the era of radio. He literally burned up a generator in Colorado Springs when tuning up a transmitter that would later light a few hundred-watt bulbs 25 miles away.
For efficient wireless transmission to work, you’d need a medium that is highly directional, harmless to humans/animals in its path, and immune to scattering or attenuation from the atmosphere or objects in its path. In other words, you need a medium that hasn’t been invented yet.
May 4th, 2008 at 7:27 pm
I do not think this is very far fetched and I do believe it will start with smaller gadgets. I do not believe that battery companies will take kindly to the idea oddly unless they have patent on these methods.
May 4th, 2008 at 9:05 pm
How did Tesla wirelessly power the worlds fair? Seems this day and age we should be able to make leaps and bounds to where Tesla left off. Could it be that he was just that brilliant?
May 5th, 2008 at 4:04 am
Why are massive brains busying themselves with wireless power transmission for cell phones before they have solved the stupidity of every cell phone coming with a charger that is incompatible with every other brand and model of cell phone – and also incompatible with every other device (shaver, toothbrush, camera, etc.) that requires a charger to convert household current. Talk about waste! And don’t even get me started about remote control devices.
May 5th, 2008 at 4:14 am
“P Bartlett said on May 2nd, 2008 at 6:24 pm
One of the seven signs of bogus technology is that the inventor pitches the technology directly to the media rather than peer reviewed journals.
Thats what we have here. The guy is a charlatan.”
What a buffoon you are Mr. Bartlett. As everyone knows, the intellectual tyranny of the “peer review” system has been systematically used to stifle innovation and preserve the economic monopolies and status quo of the elite, to the detriment of human progress and wellbeing. Check out suppressed discoveries in the fields of free energy, anti-gravity, cancer cures, etc.
May 5th, 2008 at 5:30 pm
Not the same technology as Tesla but the same concept. The question is whether or not it is safe.
May 5th, 2008 at 6:19 pm
This idea is promising. But there are major hurdles to high efficiency. Simple logic shows that unless the transmitted power can’t be radiated away then it needs to be directional. Simple physics can show no radiation equals low frequency which means high loses. Sure you can set up, non practical, ideal conditions in a lab but thats not solving the problem. There are major hurdles to implementing this technology that I do not see addressed.
I strongly urge anyone who thinks Tesla had it all figured out to check the later patents (hell try and build the things and get them to work). Most Tesla fans only read his “popular” books like “the problem of increasing human energy”. The latter to researchers are a bit like Nostradamus’s prophecies. Sure he hits some right, but knew it all? Well only so far as Leonardo knew all about assembling helicopters.
May 5th, 2008 at 10:37 pm
This guy got his idea from watching ‘Southland Tales’
May 5th, 2008 at 11:06 pm
That’s right, directional is the key. There is a small company out of Sunnyvale, Ca called PowerBeam Inc. that is doing just that, they are using lasers to transmit wireless electricity and it’s for the reason’s stated by “An Honest Chap.” It is simply more practical.
May 10th, 2008 at 6:03 pm
This just encourages the incredibly wasteful, even pathological (in terms of our species) need for “more power” (and laziness too) whereby everyone wants it now and to hell with the cost. This wasteful use of power (70% efficiency???) just because some professor didn’t want to get off his butt and didn’t remember to plug in his device either is an idea that should go down as another reason the world hates us as wasteful, selfish, arrogant and lazy or as another reason we will have annihilated ourselves with countless frequencies of electromagnetic radiation.
May 10th, 2008 at 10:53 pm
I can think of a much simpler way to utilize this: A phone charger could be a small pad, similar to a mousepad, plugged into an electrical outlet- the top would be composed of the wireless power transmitter and a pressure sensor. When someone sets his phone onto the charging pad, the pressure sensor would turn on the power transmitter and begin charging the phone. When the phone is taken off the pad, the pressure sensor will automatically stop transmitting the power.
This would take care of problems such as poor transmission over long distances, others feeding from the power (the way people use insecure WiFi) and wasting unnecessary power.
May 13th, 2008 at 9:48 pm
Ya gotta do 90% eff over miles, not yards!! Tesla would tweak you!
May 13th, 2008 at 11:57 pm
Hey thats great! Too bad Tesla invented this in the early 20th century, but lost funding after they found out you can’t meter it, and he intended to make electricity available for everyone in the world for free. Wireless energy is nothing new, the idea of it has just been forgotten.
May 21st, 2008 at 5:17 pm
O really? Why didn’t they use tesla’s “invention” to meter it the local level with a receiver outside each house. Thus saving millions on power line loses and using almost the same scheme they use now. Rogue receivers could be made illegal and easily tracked down with a weak local transmitter (easily financed through the savings). Basically your talking crap, tesla ideas where good in his time but decades behind ours. If you don’t understand this you are in the same category. You can prove me wrong by making a fortune with this “forgotten” technology. Don’t give up the day job in the meantime.
July 9th, 2008 at 5:49 pm
look to the future cities of the world this technology can lead to pure electric transportation(cars, planes, ships… even a freakin segway) that would never need recharging and def. no pollutants to our already decaying atmospere
July 27th, 2008 at 6:39 pm
Q: Why was Tesla right about the world’s power grid but wrong about his wireless vision?
Q: Why was JP Morgan, Edison and the other usual cast of super rich character’s so determined to ensure Tesla received no further funding to complete his Long Island tower experiment… in other words, why didn’t they allow him to fail after JP Morgan asked Tesla “where do I put the meter”?
Q: If Tesla’s wireless / beam energy is so inefficient and not useful, why have we funded and relied on it for military applications related to HAARP? (SDI, sonar to submarines, weather modification, Tesla Howitzer)… does this mean that his technology is only efficient for destructive military applications? If so, please explain.
July 31st, 2008 at 11:54 pm
can we have the circuit diagram of this wireless power trassmission?
August 19th, 2008 at 6:22 pm
Uhm.. if you put two resonating bodies in the room with the “originator”, will they only resonate half as much? Does your radio “suck energy” from the airwaves? And if there is sold to many radios, then you have to crank up the signal?
It seems to me that energy is not lost into nothingness, but scattered into a sea of energy. And we simply don’t know where to look for it. The wires are a track for the energy. But maybe that just diminishes the energys potential. However it is making it more traceable, accountable and predictable. But is that what the energy wants? Seemingly, the energy prefers the wires, but it needs constant feeding from the outside. Captured it gets vampiric. Unlike in the wild.
September 1st, 2008 at 2:46 pm
if you guys want a whole zip file packed with teslas patents you can get a real idea into the mindset of a pioneer, and maybe futureengineers can help us off our reliance on the man! there’s a fuel all around us that needs to be unlocked!
post whether you want to the ZIP and ill post the link
August 10th, 2009 at 12:34 pm
tell me how it can be transmit and how it can be received …….. with full images
August 10th, 2009 at 12:37 pm
tell me how it can be transmitted and receiver
November 23rd, 2009 at 2:56 pm
All of these ideas are pretty impracticle. PowerBeaming, Microwave transmission, magnetic resonance coupling, the big break through will come when they figure out how to manipulate particles to a degree where they can transmit them “anywhere” they like. Sounds obvious and unrealistic but i think it’s possible. Why do you think they are putting billions and billions into the large hadron collider. Finding the Higgs Boson might enable us to do things like that ‘eventually’. Pity it is proving so illusive. Something like that, as someone said would make deep space travel and sun farms possible. I have often thought how great it would be if they could just send some kind of solar panel close to the sun and beam the energy back. Fossil fuels will one day be an interesting and sad fact of History I hope.