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

US Silent on Psychologists Role in CIA’s Tortures: Doctors
2014-12-20 21:53
Physicians for Human Rights had not received any response from the US Federal Commission to their call to investigate the role of health professionals in CIA’s torture program, Deputy Director of the organization told Sputnik. December 19 (Sputnik) — US government has not responded to calls to prosecute doctors, who participated in CIA torture program, the Deputy Director of Communications for ...
Ziolebrities: Simon Cowell donates £100,000 to Israeli soldiers to please pregnant jewish girlfriend Lauren Silverman
2014-12-20 21:00
Cowell, 54, is also planning a secret trip to Israel soon as he embraces the Jewish faith of Silverman, 36 Gala: Billionaire Haim Saban with Cowell Simon Cowell has publicly donated nearly £100,000 in support of the Israeli army. The X Factor boss pledged the cash to the Friends of the Israel Defense Forces at a US fund-raiser in Beverly Hills. The lavish gala ...
Former Chief Security Officer for NewsCorp: N. Koreans Not Behind Sony Hack, Interview Leak
2014-12-20 2:17
Hemanshu Nigam, a former federal prosecutor and former chief security officer for NewsCorp/Fox studios, says North Korea isn’t behind the Sony Hack. Nigam gave several bullet points for why the hack was likely an inside job. Attack code borrowed from a previous attack on Seoul, that’s why it’s in Korean. Private hackers typically borrow malicious code from other hackers.Nations state attacks follow ...
Sony Fires Back at Obama: Actually We Did Call the White House – Several Times
2014-12-20 2:13
Sony fired back at Obama after the press conference saying they had several conversations with the Obama White House before and after the movie was canceled. Via The Hollywood Reporter: After President Obama criticized Sony for its decision to cancel The Interview's release after theater chains decided not to show the film, the studio has issued a statement elaborating on the move. “The ...
The Bankster International
2014-12-20 1:55
Geopolitical analysis, the art of explaining power relationships through the prism of impersonal geography, can be a helpful tool for observers of the Great Game – but it also has its limitations. A case in point is the renewed US-Russia confrontation. Think tanks and policy insiders easily sell the narrative that from the dark days of the Cold War to ...
More News »