Emerging Tech

The advent of wireless power


A team of researchers from MIT has demonstrated a future in which true wireless power can be a reality when they recently lit a 60-watt light bulb from an unconnected source about seven feet away.

Dubbed WiTricity, (Can someone please give the PR folks a call to figure out a better name?) the research was published in Science Express, an online publication of the prestigious journal, Science.

By utilizing a pair of magnetically coupled resonators, it is possible to emit a non-radiative magnetic field that is oscillating in the megahertz range. The receiver coil , which is tuned to resonate with this field, receives the transmission. This arrangement means that very little power not picked up by the receiver is wasted or radiated uselessly off.

According to the researchers, power levels sufficient to run a laptop can be efficiently transmitted across a room even without direct line-of-sight.

Still, it could be many years before we see such a technology on the market.

But just imagine for a moment when such a technology is finally ready for market release. How do you think it would change the way you perform your daily work in particular, and with the IT landscape in general?

Join the discussion.

About

Paul Mah is a writer and blogger who lives in Singapore, where he has worked for a number of years in various capacities within the IT industry. Paul enjoys tinkering with tech gadgets, smartphones, and networking devices.

50 comments
ntwrkurwrld
ntwrkurwrld

Isn't this what Tesla discovered?

ntwrkurwrld
ntwrkurwrld

Isn't this the technology Tesla discovered, and the government put the stop on? Sorry... I didn't read some of the other posts up above about Tesla. Forget this posting....

shazzam
shazzam

Can you say: Nicoli Tesla anyone? http://www.teslasociety.com/index.html Wireless electricity... Static Charging vs Manetic Induction... Old Idea, new approach... Interesting

ralphclark
ralphclark

Yeah that was the first thing I thought of too, but the gee-whiz aspect of Tesla's idea was transferring energy via longitidinal waves, which is quite low efficiency, and can't be done through free space at all; IIRC they need to travel along a surface between two media with different permeability, or something like that. Anyway the MIT device isn't doing that. I think.

georgeou
georgeou

Normal induction only works at extremely close distances. We're talking about almost touching for it to work. This MIT project is working at 7 feet. At that distance normal induction wouldn't work at all.

johnstont
johnstont

Clap-on, Clap-off! Will the clapper make its way to the crapper if this takes off?

paulmah
paulmah

But just imagine for a moment when such a technology is finally ready for market release. How do you think it would change the way you perform your daily work in particular, and with the IT landscape in general?

That one guy...
That one guy...

Wireless energy transfer has existed for Eons. Literally. and it transferred electricity far longer than 7ft. It is called Lightning.

mauritz.scherman
mauritz.scherman

Copper/cable theft could be erradicated, if the tech is commercially applied. The NC province in South Africa exported R 77M copper in 2005/6, yet has no copper mines in the province. How would circuit breakers function?

Neon Samurai
Neon Samurai

This seems more akin to the way networks are setup now. You've a wireless router but it's fed by a cable connection. I'm guessing that in the same fashion, you'd have a wireless energy transmitter fed by a cable connection. The breaker would be along the cable some place.

nrobanl
nrobanl

I don't mean to sound all Hollywierd "Matrix"ish, but electro-biochemistry in the human body nervous system (if not in cellular level metabolism) allegedly causes EM fields and/or radiation around a living body that is somehow detectable at distance by some appropriate sensors or scanners. I admit, I haven't researched the validity or science around the so-called human "auras", but if that's real science and exists, perhaps that "radiation" is an exploitable untapped source for energy conversion and wireless power... hmmm... whattaya know about that??

Neon Samurai
Neon Samurai

I think it was either Cyberpunk or Blue Planet (er.. I didn't just use RPG references.. honest). One of the sci fi techs was biomechanical generators to power cybernetic implants. You bend your leg, the generating device uses that to "spin it's turbine" (if you will) and your implant get's it's juice. Ok, not remotely real science but it's another place I've seen mention of generating energy from normal body movement. Your idea can't be any less plausable. I may consider if any ill effects could be caused by drawing energy off the body; maybe our auras are for some function that medical or metascience hasn't even come close to considering.

ralphclark
ralphclark

"maybe our auras are for some function that medical or metascience hasn't even come close to considering" Our AURAS? Well never mind, we can probably cure our aura-sickness by balancing coloured chips of rock on our nipples. Or aromatherapy. Or by rattling a bean-filled gourd on a stick while chanting "ooga wooga". Pfffft.

TJ111
TJ111

This technology is over 100 years old. It's not new, Nikolas Tesla invented it in the late 1800s, and actually built a working wireless power plant for testing purposes. The fact of the matter is that society and industry weren't ready for it. Maybe this time we won't be idiots. Tesla was an amazing inventor, and often chastised Thomas Edison and Albert Einstein for their theories and methods. If your in to technology (which if you come to this site you no doubt are), I'd recommend doing some research on him.

nrobanl
nrobanl

When I was a gradeschool kid in the 1960s, I recall a fascinating live audience demo I saw (at either S & T Museum in Chicago, IL, USA or St. Lous science center, I forget which) where the speaker gave us a live demo of induced EM field levitating metal disk. I'm almost certain it worked on Tesla's principles, and this large metallic disc about the size of a trash barrel lid, was levitated off the floor at least a foot or two for a few seconds. I believe he stated that it did NOT have to be a ferrous metal or alloy, and maybe the disk was Aluminum (lighter weight of course), but I've never figured out how that (non-Fe) is possible. The big problem and drawback which was also evident and explained, was the tremendous heat build-up in the effected metallic object which almost glowed red in just a matter of a few seconds levitating in the induced "field". After 2 generations (nearly a half century) I've never seen such a demonstration reproduced anywhere, live or in any of the media. I'm sure it must be not a rare phenomena or field of science, just relatively uncommon knowledge to lay people. Guess I'll have to go research it myself, if only to learn what tech advances have progressed since then. Maybe (hopefully) the heating (energy loss) problem has been mitigated. I want a low-temp personal transport lev-vehicle too!!!

tokunbo007
tokunbo007

A friend and I were discussing some 2-years ago on wireless electricity/power that doesn't shock/electrocute. And yes, with the MIT research that is non-line of sight. The next question is: if there are two(2)such or even multiple devices in the same room, placed at different locations, with their power sources also at different locations etc, how does device-A know it has to source its power from source-A and device-B from source-B etc, without interference. I was thinking if I.P could come into the picture.

paulmah
paulmah

Extrapolating from the fact that it works by resonance, and from what little I know of it, I would imagine that if you have 3 devices "tuned" to the same frequency and only 1 power source, then the power would somehow be shared by the devices. Most probably likely the nearest one would get the most juice?

ralphclark
ralphclark

I've been looking the wikipedia article on "near and far field" at http://en.wikipedia.org/wiki/Far_field "the near-field, if it must be seen in quantum terms, may be thought of being composed of virtual photons, which have a more evanescent existence, and which do not remove energy from the transmitter, unless they are absorbed by a close charge which signals the loss back to the antenna (for magnetic components, for example, this is simple induction-coupling)" Right here is the key insight: for the near field, energy transfer really does only happen if there is a receiver there to suck it down. (And if we can trust the author's explanation, the carrier medium is a genuine EM field.). This makes me think of what happens when you are listening to a weak station on the radio and you put an earthed or capacitative conductor (such as your hand) near the receiver, and the station fades the nearer the conductor gets to the arial. I always thought this was a very weird effect. Is energy being drawn out of the receiver via near-field coupling? How could this be? The receiver isn't doing the transmitting so how can it give up energy to another arial? But as the wikipedia article notes: "Remarkably, by the principle of reciprocity the pattern [of near and far fields] observed when a particular antenna is transmitting is identical to the pattern measured when the same antenna is used for reception." It looks to me like the very same near-field coupling effect. The fact that you are drawing energy out of a field generated hundreds of miles away via a purely LOCAL effect, is really no stranger than the fact that you can selectively pull energy out of the field at all.

ralphclark
ralphclark

George, in a comment below, suggests that there may be a low theoretical ceiling on efficiency. I don't know the physics of near-field inductive coupling at all well but for something like this (that seems to work almost "magically") until they can demonstrate 90% efficiency I would be sceptical that it can be achieved. In any event I doubt they will wait for 90% before letting products hit the market. Sorry for the snarky tone - I've had the mother-in-law here all afternoon :-\

Neon Samurai
Neon Samurai

My response was based on the idea that if this where to leave the lab and be a viable technology, it would also have matured greatly from the 50% waste or so that it currently presents. What say we restate your knee jerk response based on the idea that efficiency where increased to 90% or more. Here, I'll start: For keyboard and mouse, absolutely but for CPU; go something completely different like a fluid or light based chip with no or little waste through heat generation. ok; your turn. (My snarky tone in response to your snarky tone.)

georgeou
georgeou

http://blogs.zdnet.com/Ou/?p=388 Statistics are not on the scare mongering side if you look at it in whole. What the scare mongers do with the help of the ignorant media is to find pockets of cancer near power lines. They're taking advantage of the fact that statistics are never uniform unless you're talking massive samples. We're you look at a pocket of 500 people for example, you're always going to find pockets of people with higher rates of cancer living next to a power line. But they're leaving out the fact that there are plenty of other samples of 500 people living near power lines that have lower rates of cancer than the statistical norm. In the end they all balance out to the norm. The problem is that people love using anecdotal evidence as proof something is wrong.

ralphclark
ralphclark

There's an argument about the very same thing in a nearby thread :-0 Fact is though with the MIT device they are surely doing something novel if as they claim they are managing not to just waste energy in omindirectional field emissions.

ralphclark
ralphclark

But I'm not surprised. However it is surely set to change soon. On the one hand there is a lot of political pressure in Europe now to cut down on energy wastage. On the other, I note that just about every data centre I've had to depend on at work is power constrained, i.e. they run out of power even before they run out of rack space. I would expect to see the sort of energy efficient technologies that have been developed for portable computing, being deployed in server hardware at some point in the next few years.

ralphclark
ralphclark

I understood that the "I-squared-R" power losses were effectively minimized by using a high-efficiency transformer to step up to a million volts or so between the generating station and the local domestic substation. Well I'm pretty sure that's how it's done in the UK. Where else is energy being lost?

georgeou
georgeou

40% is good enough for low-power devices that are sub 10 watts. Someone should be shot if they used these for a 60 watt light bulb though.

georgeou
georgeou

Do you know that Data Center efficiency is 50% by the time your power goes thorough the UPS battery backup, power distribution, and power supply? By the time you count cooling costs, you're down to 25% efficiency. If you can power a small ultra-light tablet computer for something like hospital usage that's in the sub 10 watt range and enable better mobility, then it will well be worth it.

ralphclark
ralphclark

...lets have all the five hundred million or so personal computers in the world running off this technology. I mean, between them they're already converting about 200 GigaWatts into waste heat. If they ran off this 60% efficient cordless power tech it would only waste another 200 GW or so. Who cares, eh?

georgeou
georgeou

Yes the alternating current will also emit its own EM field but you can shield the EM field without shielding the Magnetic field. Otherwise you won't get FCC approval for the device because it will be too noisy.

ralphclark
ralphclark

Of course you can have a magnetic field without an associated electrical field. For example this is what a permananet magnet has. But for purposes of power transfer, in order to produce induction in a receiver, a magnetic field is not enough - it has to be either moving or oscillating. The usual way to produce an oscillating magnetic field is by pushing an alternating current through a coil. This results in oscillations or waves in the surrounding electric and magnetic fields. It's EM radiation. The other way is to move the magnetic components mechanically. In general, if the point is to extract electricity then the magnetic field of the electrons on the receiving end makes them "surf" on the magnetic flux, so pushing them whough a wire. For example as in an electrical generator where the stator is magnetic and the coils are in the rotor. But the current induced in the moving rotor coil creates its own electrical (and magnetic) field and so that now emits EM radiation itself. The bottom line is, you *can* have a magnetic field without an associated electrical field but in general you *can't* transfer power without creating another magnetic field to interact with it. If the interaction is used to push electrons through a wire then there will be EM radiation. This is surely going to be the case with the MIT device. In theory you could transfer magnetic energy mechanically directly and mechanically between two magnets without inducing a current by moving one magnet while the other is coupled to a geartrain. But this doesn't make much sense if all you want to do is charge a battery.

georgeou
georgeou

Stop comparing a Magnetic field to an Electromagnetic field because they are two different things. Induction works when magnetic fields induce current in a circuit. That magnetic field could be produced by a nearby circuit with oscillating current or it could be produced by moving a permanent magnet. Radio waves are transmitted using Electromagnetic Fields, not Magnetic fields. If you think a Electromagnetic Field is the same thing as a Magnetic field, then you?re sadly mistaken. See: http://www.pbs.org/wgbh/aso/tryit/radio/radiowaves2.html Also see: http://en.wikipedia.org/wiki/Magnetic_field http://en.wikipedia.org/wiki/Electromagnetic_field

ralphclark
ralphclark

George, in response to the post immediately above this one: I am not taking any position on the EM-radiation-is-harmful debate. But as to your assertion that induction does not involve EM waves - that's tantamount to saying that it does not involve a transfer of EM energy across space. Yes I did Michael Faraday in high school, but the unification of electricity and magnetism and the propagation of EM radiation were not properly understood in terms of a dynamical EM field until the more sophisticated maths of James Clerk Maxwell's work during the 1860's. So Faraday's explanation omits any mention of waves or radiant energy. If the new invention from MIT needs to create an oscillating magnetic field, then it must surely do so using a coil. But regardless of whether you even have a secondary coil, if you push an alternating current through the primary, it still emits EM radiation. How else do you think a radio transmitter works?

georgeou
georgeou

See: http://en.wikipedia.org/wiki/Electromagnetic_induction You induce current from one circuit to another circuit without the two circuits touching each other. That is not the same thing as Electromagnetic Radiation. It's the change in flux over time that induces an electromotive force in the nearby circuit. Electromagnetic Radiation is not harmful to humans. If it were proved to be harmful, power companies and cell phone companies would owe trillions of dollars in lawsuits. If it were harmful, people who live near 50,000,000 mW radio stations would have serious side effects. If living near a 50,000,000 mW radio station doesn't hurt you, a 50 mW wireless Access Point won't harm you either.

ralphclark
ralphclark

I have a question about that last assertion George. Induction is the effect where an electrical current is created in a conductive material (usually, for efficiency's sake this will be a coil with or without a ferromagnetic core), this being "induced" by a change in the strength of the ambient magnetic field, or movement of the inductor through a static magnetic field. The mechanism relies on the force interaction between the ambient magnetic field and the spin-related magnetic moment of the electrons in the conductor. In order for the effect to be sustained, the change in magnetic field (or the inductor's movement through it in the case of an electricity generator) is usually cyclic i.e. oscillatory. But an oscillating magnetic field is always accompanied by an oscillating electrical field. The one cannot occur without the other. The two together are what we call EM radiation. Which is exactly the same thing as in power lines, cell towers, and microwave ovens. With a conventional inductive coupling, the alternating current in the primary coil radiates EM energy somewhat wastefully in all (well, most) directions. Not all of the radiant energy is transferred to the secondary coil. As I (barely) understand it, the difference with this new invention is supposed to be that due to some sort of resonance effect, the energy is *not* being radiated in all directions but is somehow being released only to a tuned receiver. The quoted 60% wasteage is then presumably due to hysteresis losses etc (resulting in waste heat) in the transmitting and/or receiving inductors. But the mechanism of transfer is still an oscillating EM field, i.e. plain old transverse EM radiation. Isn't it?

georgeou
georgeou

"We already know that people that live next to power lines are more likely to develop cancer and children are more susceptible to birth defects. Maybe I am just ignorant, but wouldn't electricity sent through the air have the same effect?' First of all, NO there is no relationship between higher cancer rates and living next to power lines. People claim that, but no one's ever proved it. The fact that you might have pockets of higher number of cancer is balanced out by pockets of lower cancer rates living next to power lines. That is the nature of statistics. You should never expect uniform consistency. Having a natural variation is very normal. The problem is that you have a few people cherry pick some of these hotspots and claim it's proof that power lines cause cancer. Second, the device being talked about here is electromagnetic induction. It has nothing to do with the kind of electromagnetic energy coming from power lines, cell towers, or microwave ovens.

Neon Samurai
Neon Samurai

Why be limited to the heat disipation and restrited flow of electrons in the CPU? Run the CPU on light or some other non-electron technology. By all means though, the things in a machine that have to be eletricity based; power 'em all.

BruceLaBonte
BruceLaBonte

Although it is not a "doomsday" device that could kill off the entire world population, this technology might be harmful to some people who have implanted medical devices in their body. For example, I cannot have an MRI because it would mess up my pacemaker, and that would definitely be hazardous to my health! It might depend on the strength of the magnetic field that is used.

gwcarter
gwcarter

Any time a current flows through a conductor an electromagnetic field is emitted around the conductor, as well as an electrostatic field. If the current fluctuates the EM field induces a similar current flow in any neighboring conductor. This emission is also called "radiation", whether or not the primary current fluctuates. RF radiation is just the field fluctuating at a higher rate than power radiation, except that it is more efficient. That is why radios work. Power cannot be transferred in this way efficiently without a resonant circuit in the reciever, but the emission of the magnetic or static field is "Radiation". Power cannot be transferred without it. As far as the Cancer thing, no one has ever advanced a causal chain to prove the speculation. Statistics are not proof, just tools for media types to use to scare the general public.

tokunbo007
tokunbo007

yeah, now we're talking. Imagine a CPU without power cables, no cable from the powerpack to the board etc, or maybe no power-pack even.

Tig2
Tig2

I am a cancer survivor. I have never lived in close proximity to power lines. Cancer is a question of what your genetic markers are first. Can outside influences have affect? Sure. But "Love Canal" stories manifest some pretty specific maladies. I would suggest that power lines, unless they are related directly to areas of high concentration of a cancer type where the histories of the sufferers show no genetic connection to cancer, are not causal to the appearance of cancer. Ingesting tainted source is one thing. Being in the vicinity of a power source that is not radio-active is another. I would want to see more conclusive studies and so far, they haven't been done. I am not saying that it is impossible. I am saying that without facts- real, peer reviewed, science- you are reading opinion. And with facts and peer reviewed science, you are simply reading educated opinion.

faradhi
faradhi

It just comes more naturally for some. I guess I am blessed with a talent. It just seems like every new technology comes with an unfounded doom and gloom warning, mostly out of ignorance and fear. I guess I just acted with a knee jerk reaction. Sorry I was harsh.

JohnMcGrew
JohnMcGrew

There is not much good science to correlate cancer to power lines. There were headlines back in the early ?90s due to a Swedish study that came to that conclusion. However, that study has since been discredited. The whole power line-cancer connection is not mostly supported only by the tort bar. Either way, I doubt that in a society where there are still a number of people who are convinced that the low power output from a cell phone will damage you would tolerate the idea of millions of higher-powered transmitters powering devices of all sorts.

Locrian_Lyric
Locrian_Lyric

it's like pushing water through a series of leaky pipes.

besmithus
besmithus

I was simply expressing a concern and asking a question... that is no call to be a jerk about it

nrobanl
nrobanl

Article states MegaHertz frequency which means AC oscillation, right? Static bar magnets create standing magnetic fields around their cores (likewise planet Earth?) which can repel other fields and apparently certain particles or X-radiation, but they themselves do not radiate, correct? DC current in conductors (wires) create standing electromagnetic fields around them, but do not radiate, if I understand correctly. I've never heard of standing magnetic fields being suspect as biologically harmful to living tissue. However, if this new technology involves coupled resonance with AC alternating wave power over distance, then that pretty much demands and requires radiation. Am I not correct about that? If so, how is that not RF radiation, subject to power loss, signal interference, interception, etc. etc. ?

paulmah
paulmah

It would be great to have those nifty gadgets on your desktop and without any cables, not even to recharge, and with no need for batteries to boot!

faradhi
faradhi

We are surrounded by a magnetic field. The earth creates a powerful one to protect us from solar radiation. Additionally, MRIs use magnetic fields. How about reading the article and researching magnetic fields before pulling this thing is going to kill everyone card.

faradhi
faradhi

By the time the devices make it to the market it would likely be more efficient. Further, in all likelihood this technology would likely be used for low power devices such as mice, keyboards and even RFID tags.

besmithus
besmithus

Does anyone think that this may be a bad thing due to radiation? We already know that people that live next to power lines are more likely to develop cancer and children are more susceptible to birth defects. Maybe I am just ignorant, but wouldn't electricity sent through the air have the same effect?

ralphclark
ralphclark

My god - if you had two of these devices in close proximity it would set up a resonance feedback loop that could destroy two thirds of the universe. The only way to stop it would be to REVERSE THE POLARITY! ;-) But seriously folks: this technology is dead before it even begins. The energy transfer to the light bulb in the demo was achieved at an efficiency of only 40%. Meanwhile the world is moving towards low-energy, high efficiency devices and electronics manufacturers are even being lobbied to remove "standby" power state from their consumer products because the trickle current consumed by all those millions of TV sets and hi-fi's mounts up to a huge energy drain. I frankly don't think the world will welcome a charging system which throws away more electricity than it transfers.

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