Physicist moots wireless electricity
2006-11-28 0:00

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

Why a Caucasian-Japanese is not Percieved as Japanese
2015-08-04 2:15
The Japan Times has a hilarious article about a White guy who is angry and upset at the horrible and racist world we live in because customs agents and border agents are questioning his "right to be Japanese." It's seems that Debito Arodou's experience at border crossings suggest that no one takes a White guy seriously, for claiming to be Japanese. Hmm, ...
"Open the border - we're going to the UK!" Chanting mob of 200 storm Eurotunnel
2015-08-04 1:25
Migrants make their way towards the Tunnel entrance in the early hours of Sunday morning An organised mob of 200 migrants charged into the Calais entrance of the Channel Tunnel early yesterday, chanting ‘open the borders’ and demanding to be allowed into Britain. They tore down fences and charged past police, who retaliated by spraying tear gas. When the migrants were finally ...
Forgotten British Heroes Campaign
2015-08-04 0:16
The text of the letter from the Forgotten British Heroes Campaign to the Israel ambassador in London, Daniel Taub. This will be delivered to the Israel Embassy on Saturday 1st August, the day on which the Campaign will hold a wreath-laying and then a meeting at the site of a notorious Zionist terrorist bombing near to Trafalgar Square (the former British ...
Baltimore Murders Tie Records After Freddie Gray Killing, 45 Killed In July To Make It The Deadliest Month In At Least 45 Years
2015-08-03 23:14
The number of people murdered in Baltimore hit a record-tying 45 homicides for the month of July, the Baltimore Sun is reporting. The number is an uptick that follows a trend of increased violence in the city in the months after the Baltimore riots that resulted from the death of unarmed black man Freddie Gray on April 12. The increased violence in Baltimore, which was already one ...
Executive arrested over disappearance of $390 million in Bitcoins
2015-08-03 23:38
Mark Karpeles, head of collapsed MTGox Bitcoin exchange held by Japanese police Japanese police on Saturday arrested Mark Karpeles, head of the collapsed MtGox Bitcoin exchange, over the disappearance of about $390 (£250 million) worth of the virtual currency, local media said. France-born Karpeles, 30, is suspected of having accessed the exchange's computer system and falsifying data on its outstanding balance, ...
More News »