Commercialization is just one problem that comes to mind.

The human central nervous system also consists of electro magnetic subsystems which respond very well to resonance. Does this mean that we will soon need to wear Faraday cages around our hearts and brains? Ever notice the side of your head heating up very slightly after a 30 minute conversation on a mobile?

Perhaps simultaneously with WiTricity, we should begin work on BodySuits and HeadGaskets. Most likely, as with mobile phones, the issue will simply be overlooked in favour of convenience.

Directional lasers w/ sensors seem like they could offer a solution.

Daniel Volkovich, Skopje, Macedonia

Hope someone investigates the effect, if any, over time on animal bodies located between sender and receptor. It would be too bad to find out the hard way that there is a negative effect.

Hotspur, NYS, US,

Remember that MIT operates in a universe where the word "efficient" means something different to what it does here. This is basically a transformer a few feet across and without an iron core. There is a reason that all other transformers are small and have iron cores.....

The real world is in any case rapidly standardising on mini-USB charger sockets. You only need to remember where _one_ of your chargers is....

Ian Kemmish, Biggleswade, UK

Ah yes, the transmission of electric power by wireless is an old idea and was investigated in the 19th century. One of its proponents was Nikola Tesla (he of AC current), who built the Wardenclyffe Tower on Long Island NY around 1900 to demonstrate the potential of power as well as telecommunications transmission. Unfortunately how to make money by charging people for receiving this free power hadn't really occurred to him and so when asked by JP Morgan, one of the financial backers, "where do you put the meter?", answer came there none. Hence money came there none from then on, and it was broken up for scrap. How to stop your neighbours from helping themselves to your paid-for wireless power will scupper this idea just the same.

Steve Hobbs, Sutton, UK

Tesla's work failed because anyone could tap the supply, and the energy companies were not having that. We should nationalise the selling of energy, switch to nuclear and renewables and use the wireless system.

Ben, York,

Why did it take more than a hundred years to make use of an old invention of a surpessed genius?!! Surprisingly a lot of us still know his name, so his credit isn't totally lost, thank god for that!

Binjie Zhao, London,

this is not new, it's tesla territory. he experimented with matching tuned coils and standing waves a century ago. most of his proven concepts were never commercialized or even taken seriously. he also invented polyphase ac current, radio control, and global power distribution using capacitance between the earth and atmosphere.

karmaduck, Tampa, FL

Nice one - something else to give us all early age cancer

Microwaves, WiFi, Mobile Phones, Wimax, and now WiTricity.

Are we intentionally trying to shorten the life expectancy of our children for short term commercial gain?

Si, Reading,

Ah yes, this idea is an old one and was investigated in the 19th Century. Nikola Tesla built the Wardenclyffe Tower on Long Island US around 1900 to demonstrate the transmission of power as well as telecommunications by radio. Unfortunately the problem of how you make money by charging people for using this free power hadn't really occured to him and the people like JP Morgan who were providing the funding had second thoughts. It was broken up for scrap.

S. Hobbs, Sutton, UK

The world of Star Trek is coming ever nearer. Science fiction writers better come up with some new material!

Stuart, Manchester, UK

What makes this unique is they are using evanescant waves. It's kind of a difficult concept to graps, but their transmitter is actually a wave guide. A portion of the energy being guided actually exists outside of the guide, which is known as an evanescant wave. At low frequencies these waves go through most anything and continue to be guided, but if you design a device that resonates with them, it will absorb the energy. Thus you have wireless energy transfer that is potentially without any radiation loss.

Greg Berman, Boulder, USA, CO

I wonder what the impact will be on power consumption... I doubt it is going to be 100% efficient - I think I read 40%? It sounds like the 'standby' thing all over again where over time, we use more and more power to do the same things.

Andy B, London,

They already have wireless speakers, Ian.

fart, no,

Good idea Ian, particularly for active speakers.

Nice to see someone is finally catching up with Tesla's idea for wireless powere distribution, he seemed to manage it over a fair distance at reasonable efficiency, odd that it has taken so long....

Kidd Garrett, Bristol, UK

it will destroy the planet in some way and we'll have to change even more lightbulbs

John Ledbury, Kings Lynn, England

In 1901 Nikola Tesla built device to transmit power without wires at frequencies of 100,000 Hz at a distance of 22 ft.

Alex Novak, London,

Difficult to tell from the report, but this sounds awfully like Tesla's work in Victorian times. How is it different?

Geoff Lake, Carbost, Isle of Skye

Develop the system to get rid of the speaker cables for Hi-Fi and surround sound systems first. It gets rid of all the ugly cables lying around a room and the speaker boxes are big enough to house the first generation resonance coils.

Ian Robinson, Grangemouth, scotland

The principle of transmitting power without wires was first demonstrated in state of New York by Nikola Tesla (after whom unit of Magnetic field strength is named) some hundred years ago. His efforts were thwarted by Edison power company which had monopoly on power distribution.

Alex Novak, London,