Physicist moots wireless electricity
2006 11 28

By Anna Salleh | abc.net.au



You may one day be able to recharge your laptop or mobile phone without having to plug it into the wall, says a US physicist.

But others say there are many hurdles before such transfer of energy means we can say goodbye to wires.

Assistant Professor Marin Soljacic, of Massachusetts Institute of Technology, will present his team's work at the American Institute of Physics forum in San Francisco this week.

Today's wireless transfer of energy, such as the transfer of light energy from the Sun for solar power or the transfer of microwaves from transmitters for communication, involve relatively low levels of energy.

But recharging devices like laptops requires a much higher level of energy. And if this was routinely zapped through the air it could 'fry' any living organisms that get in the way.

But Prof Soljacic says he has found a way of transmitting energy so that only the devices that it is recharging will pick it up, so it will not affect humans.

Instead of using traditional radiation, he wants to use the part of the electromagnetic field that is 'non-radiative'.

He says devices can be tuned to the frequency of this field and thus act as a sink for all the energy the transmitter gives out.

Prof Soljacic says this would prevent energy radiating out to areas it does not need to go to, providing an efficient and safe method of wireless energy transfer.

"The team calculates that an object the size of a laptop could be recharged within a few metres of the power source," he says. "Placing one source in each room could provide coverage throughout your home."

Prof Soljacic also thinks the technology could be used to power freely roaming robots in a factory.

Finding a 'magic' frequency
But Australian physicists, yet to see the full details of Prof Soljacic's work, are sceptical of his claims.

They say the challenge is finding a 'magic' frequency that does not also affect living organisms and thus pose possible health risks.

"You would be reintroducing all the problems that we went through with mobile phones," says Dr Geoff Anstis of the University of Technology, Sydney, referring to the uncertainty surrounding any long-term health effects of using mobiles.

"And it wouldn't be until a couple of decades that you may be happy that there isn't a significant problem."

His colleague Professor Geoff Smith agrees and says there are also technical challenges to keeping the devices tuned with the transmitters, thus preventing the general release of stray energy.

"I think this is nice physics but there's a way to go before it would be possible," says Prof Smith.

He says any changes in the surrounding environment could "de-tune" the system and stop the safe and efficient transfer of power.

Electrical engineer Dr Trevor Bird of CSIRO's ICT Centre says attempts so far to develop wireless power transfer have not been very successful.

He agrees that safety and technical barriers to wireless power systems are huge and would like further details on Prof Soljacic's proposal.

Dr Bird also says that, depending on the frequency of the field, the antenna on the device being recharged may have to be very large.

Article from: http://www.abc.net.au/news/newsitems/200611/s1789387.htm



Related Articles
Brave New World of Tesla Technology


Latest News from our Front Page

Pre-historic tokens used in conjunction with cuneiform
2014 07 22
An archaeological dig in southeast Turkey has uncovered a large number of clay tokens that were used as records of trade until the advent of writing, or so it had been believed. But a new find of tokens, dates from a time when writing was commonplace – thousands of years after it was previously assumed this technology had become obsolete. Researchers ...
Are immigration opponents Nazis?
2014 07 22
It seems the usual suspects are calling anyone who opposes unlimited immigration to be a "Nazi". The Left seems to be in constant fear of "Nazis" that lurk in public policy discussions and I assume under their beds. If you oppose any Leftist position, you are a.... take a wild guess...wait for it.... a NAZI! Tim Wise recently went ...
What Did US Spy Satellites See in Ukraine?
2014 07 22
Exclusive: The U.S. media’s Ukraine bias has been obvious, siding with the Kiev regime and bashing ethnic Russian rebels and Russia’s President Putin. But now – with the scramble to blame Putin for the Malaysia Airlines shoot-down – the shoddy journalism has grown truly dangerous, says Robert Parry. In the heat of the U.S. media’s latest war hysteria – rushing to ...
Oh, Great: Robots Are Set to Conduct National Security Clearance Interviews
2014 07 22
Advancing a career in the US government might soon require an interview with a computer-generated head who wants to know about that time you took ketamine. Psychologists at the National Center for Credibility Assessment (NCCA) are developing an interview system that uses a responsive on-screen avatar for the first stage of the national security clearance process. Initial screening for a variety ...
Is Anything on the Internet Real Anymore?
2014 07 22
Is there anybody…out there? I promise I’m a real person asking this question and typing this article…but beyond that, I can’t promise much else about anything you or I see on the Internet. This article on ZDNet, “GCHQ’s dark arts: Leaked documents reveal online manipulation, Facebook, YouTube snooping,” confirms — beyond a shadow of any possible doubt — that a barrage of ...
More News »