FRIHOST FORUMS SEARCH FAQ TOS BLOGS COMPETITIONS
You are invited to Log in or Register a free Frihost Account!


Physics Promises Wireless Power





theem
Quote:
Physics promises wireless power



Plugs and wires could soon become a thing of the past
The tangle of cables and plugs needed to recharge today's electronic gadgets could soon be a thing of the past.

US researchers have outlined a relatively simple system that could deliver power to devices such as laptop computers or MP3 players without wires.

The concept exploits century-old physics and could work over distances of many metres, the researchers said.

Although the team has not built and tested a system, computer models and mathematics suggest it will work.

"There are so many autonomous devices such as cell phones and laptops that have emerged in the last few years," said Assistant Professor Marin Soljacic from the Massachusetts Institute of Technology and one of the researchers behind the work.

"We started thinking, 'it would be really convenient if you didn't have to recharge these things'.

"And because we're physicists we asked, 'what kind of physical phenomenon can we use to do this wireless energy transfer?'."


How wireless energy could work
The answer the team came up with was "resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied.


This would work in a room let's say but you could adapt it to work in a factory

Marin Soljacic

"When you have two resonant objects of the same frequency they tend to couple very strongly," Professor Soljacic told the BBC News website.

Resonance can be seen in musical instruments for example.

"When you play a tune on one, then another instrument with the same acoustic resonance will pick up that tune, it will visibly vibrate," he said.

Instead of using acoustic vibrations, the team's system exploits the resonance of electromagnetic waves. Electromagnetic radiation includes radio waves, infrared and X-rays.

Typically, systems that use electromagnetic radiation, such as radio antennas, are not suitable for the efficient transfer of energy because they scatter energy in all directions, wasting large amounts of it into free space.

To overcome this problem, the team investigated a special class of "non-radiative" objects with so-called "long-lived resonances".

When energy is applied to these objects it remains bound to them, rather than escaping to space. "Tails" of energy, which can be many metres long, flicker over the surface.

"If you bring another resonant object with the same frequency close enough to these tails then it turns out that the energy can tunnel from one object to another," said Professor Soljacic.


Wireless energy transfer has been thought about for centuries

Hence, a simple copper antenna designed to have long-lived resonance could transfer energy to a laptop with its own antenna resonating at the same frequency. The computer would be truly wireless.

Any energy not diverted into a gadget or appliance is simply reabsorbed.

The systems that the team have described would be able to transfer energy over three to five metres.

"This would work in a room let's say but you could adapt it to work in a factory," he said.

"You could also scale it down to the microscopic or nanoscopic world."

Old technology

The team from MIT is not the first group to suggest wireless energy transfer.

Nineteenth-century physicist and engineer Nikola Tesla experimented with long-range wireless energy transfer, but his most ambitious attempt - the 29m high aerial known as Wardenclyffe Tower, in New York - failed when he ran out of money.




Wireless power for gadgets

Others have worked on highly directional mechanisms of energy transfer such as lasers.

However, these require an uninterrupted line of sight, and are therefore not good for powering objects around the home.

A UK company called Splashpower has also designed wireless recharging pads onto which gadget lovers can directly place their phones and MP3 players to recharge them.

The pads use electromagnetic induction to charge devices, the same process used to charge electric toothbrushes.

One of the co-founders of Splashpower, James Hay, said the MIT work was "clearly at an early stage" but "interesting for the future".

"Consumers desire a simple universal solution that frees them from the hassles of plug-in chargers and adaptors," he said.

"Wireless power technology has the potential to deliver on all of these needs."

However, Mr Hay said that transferring the power was only part of the solution.

"There are a number of other aspects that need to be addressed to ensure efficient conversion of power to a form useful to input to devices."

Professor Soljacic will present the work at the American Institute of Physics Industrial Physics Forum in San Francisco on 14 November.

The work was done in collaboration with his colleagues Aristeidis Karalis and John Joannopoulos.

llobo1
Yeah!! no more wires to trip over/ get tangled up in etc. Can't wait for the day. Given such as simple idea for it why has it taken so long for us to get this far? It is well known that electromagnetic waves such as light can produce electric currents to run through metal recievers.
darknight985
uhm thanks for the snippet, but a few questions.

1. Is that the full article?

2. Can i have the URL to the site please?

if you can just PM the URL it would be cool if you did

Thanks
jeanoradean
sounds pretty cool, almost too good to be true. It would really help not having to put extension cords all over the place, or not having to recharge your phone or laptop....when can we expect the first real applications of this technology?
Liambaby
Not forgetting that scientists are also working on quantum computers using light to transmit data. But then again, with the advent of personal computers experts were predicting paperless offices, with a dramatic cutdown on paper usage and production. 30+ years on we are still awaiting that particular phenomenon. I can see wireless transfer of power and data happening, it just may take a while.
ZealousZ
would we then be able to steal wireless power from neighbours??
cong06
does anyone know what the effiency of this would be?

As far as stealing it? They could probably just encrypt it like wireless internet.

Quote:
"If you bring another resonant object with the same frequency close enough to these tails then it turns out that the energy can tunnel from one object to another," said Professor Soljacic.

that seems like close range to me. I'm not sure how that translates to the long range (29m) that they were talking about.

I'm also trying to figure out exactly how the tunnelling would work. It seems kinda fishy to me. not that I don't think they'll finish. I hope they do.

Quote:
However, Mr Hay said that transferring the power was only part of the solution.

"There are a number of other aspects that need to be addressed to ensure efficient conversion of power to a form useful to input to devices."

can anyone think of other things that could slow it down? I feel like this was the hardest step....
Soltair
I've seen such a prototype in a science fair.

For you guys, just a small test: if you have a spare light bulb somewhere and a microwave, fill a glass of water then put it with the bulb into the microwave and start it. The bulb will supposely light up (the water is there to prevent the overheating of the bulb).

I think it has something to do with magnetic fields or some electromagnetic waves. The prototype also lighted a bulb from a distance with such a field, but had a very limited range.
Indi
ZealousZ wrote:
would we then be able to steal wireless power from neighbours??

That's the spirit. ^_^ That's how you tell the difference between a physicist and an engineer.
cong06
Indi wrote:
ZealousZ wrote:
would we then be able to steal wireless power from neighbours??

That's the spirit. ^_^ That's how you tell the difference between a physicist and an engineer.


meaning the Engineer would worry about that? I guess that's true.
maclui
Impossible, nobody has ever done that. Because it cannot be done. Simple. Imagine all the wonderful aplications it may have. Military, space exploration, underwater and of course simplicity at home.
cong06
maclui wrote:
Impossible, nobody has ever done that. Because it cannot be done. Simple. Imagine all the wonderful aplications it may have. Military, space exploration, underwater and of course simplicity at home.

That's pretty....bold.

Alot of people said that before the airplane was invented, and countless other inventions. You can't just say "it can't be done," if you want to be taken seriously that is.
Sharpe
They can do it, but will it be efficient enough to bring it to the market anytime soon?

It sounds real nice, but I don't like wireless. I will never use that when I buy my own house and it is on the market. I'm all for more technology to make things simpler, but not for useless technology as this appears to me.
Wires are just alot easier. Don't forget that wireless power just adds more components to break and it costs even more time to figure out what is wrong.

The supply?
The fuses?
The electronics in the wallsocket?
The electronics in the device?
The device itself?

What can go wrong with wires going to a wallsocket where a simple plug is inserted with more simple wires to feed a device it's current
Indi
cong06 wrote:
Indi wrote:
ZealousZ wrote:
would we then be able to steal wireless power from neighbours??

That's the spirit. ^_^ That's how you tell the difference between a physicist and an engineer.


meaning the Engineer would worry about that? I guess that's true.

Exactly. ^_^ Science stops after answering "how is it possible?". Engineering picks up with "how can we make this work (economically and practically)?" and "what are the social implications of this technology?".

The scientist would figure out how to transmit power wirelessly, then dust his hands off and wait for the awards. The engineer would figure out how to design marketable transmission and reception stations, worry about beam alignment (assuming a coherent beam), interception (stealing power), hazards (is the beam dangerous?), social and environment issues (what will happen to the environment, the society, the economy, the political landscape, etc. if this technology becomes real) and so on.

"Is it possible?" is only the first question. Answering "is it practical?" with "yes", taking into account all the broader effects of the technology on the world, takes just as much work, if not more.

(And of course, part of being an engineer is being just a little bit "ghetto" in your thinking. You have to look at your device/technology and say: "what would happen if i threw it in a pool... or smashed it against a wall... or took it apart with a hacksaw and icepick?" If the answer to any of those is "it would explode"... well... you need to know that before you start selling them. And also important are questions like: "how easy would it be to steal? Could i use it to steal something else... or destroy something? What if i released the safeties? How hard is it to remove the safeties?" Thinking like a criminal, an overly-curious fool or a violent neandertal is helpful to an engineer, believe it of not.)

(This is evidenced by our curiously vigorous relationship with certain BEvERages.)
wernichtfragt
i know that scientists in the past (maybe 40 years ago) were talking about power stations in the earth's orbit which would create power from the un-filtered (no air in space) radiation of the sun and convert it to microwave and send it directly to antennas on earth ;)

funny

just imagine the power transmitter would get out of place and point to somewhere else than the power receiver...... the radiation would go down somewhere in central park or in london zoo or would melt the statue of liberty.... or simply an airplane would fly through the microwave beam

i think sending energy through the air would always cause interception problems..... with your bodies......maybe heat them up or create sickness in your brain.....

depends on the frequency..... xray is known to cause cancer
also is radar...... same with ultra-violet....
wlan power is to weak to be compared .... also UHV and radio

remember (your cell phone transmits 1 w of power in all 360 degrees)
powering your stereo by the pool would require to transmit about 20 watts in one single direction (the bundelled beam is much more powerful and thus harmful)

live on earth is only possible because the air that surrounds us does
filter out a broad sprectrum of harmful (yet deadly) radiation from outer space (mainly from the sun)...... why should we now artificially create similar radiation on earth just to power our gameboy wirelessly ??? wouldnt that be dumb???
Daniel_78
The electical and magnetical field strength would be much more higher as the human protection norm for EMC would allow. The energy consumation of every device should be nearly zero. There are some troubles in RFID tags technology for transmitting the energy - and this energy is really low. Physically it's not possible to transmitt energy by electromagnetics wave as long we have international limits of E- and H- Fields.
Related topics
Theorem On Salary
Theoretical Scientific Evidence For the Existence of God
Is Nuclear Power the future?
Perpetural Energy
Dell D420
Joe Cell - cold unlimited power?
Wireless Signal Dropout
Can you be psychic?
[tecnologia] Adeus cabo de energia
What Runs The Xbox 360 And The PS3 ..... Which Is Better ?
Wireless Electricity : The future of power?
Wireless Electrity
Krishna's Finesse : p4
Smart Grid
Reply to topic    Frihost Forum Index -> Science -> General Science

FRIHOST HOME | FAQ | TOS | ABOUT US | CONTACT US | SITE MAP
© 2005-2011 Frihost, forums powered by phpBB.