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Wireless Energy is coming

Wireless Electricity is coming

US researchers have successfully tested an experimental system to deliver power to devices without the need for wires. The setup, reported in the journal Science, made a 60W light bulb glow from a distance of 2m (7ft).

WiTricity

as it is called, exploits simple physics and could be adapted to charge other devices such as laptops.

“There is nothing in this that would have prevented them inventing this 10 or even 20 years ago,” commented Professor Sir John Pendry of Imperial College London who has seen the experiments.

“But I think there is an issue of time. In the last few years we have seen an exponential growth of mobile devices that need power. The power cable is the last wire to be cut in a wireless connection.”

Professor Moti Segev of the Israel Institute of Technology described the work as “truly pioneering”.

Energy gap

The researchers from the Massachusetts Institute of Technology (MIT) who carried out the work outlined a similar theoretical setup in 2006, but this is the first time that it has been shown to work.

“We had a strong faith in our theory but experiments are the ultimate test,” said team member Assistant Professor Marin Soljacic.

“So we went ahead and sure enough we were successful, the experiments behave very much like the theory.”

Wireless power promise

The experimental setup consisted of two 60cm (2ft) diameter copper coils, a transmitter attached to a power source and a receiver placed 2m (7ft) away and attached to a light bulb.

With the power switched on at the transmitter, the bulb would light up despite there being no physical connection between the two.

Measurements showed that the setup could transfer energy with 40% efficiently across the gap.

The bulb was even made to glow when obstructions such as wood metal, electronic devices were placed between the two coils.

“These results are encouraging. The numbers are not far from where you would want for this to be useful,” said Professor Soljacic.

Power cycle

The system exploits “resonance”, a phenomenon that causes an object to vibrate when energy of a certain frequency is applied. When two objects have the same resonance they exchange energy strongly without having an effect on other surrounding objects. There are many examples of resonance.

How wireless energy could work

“If you fill a room with hundreds of identical glasses and you fill each one with a different level of wine each one will have a different acoustic resonance,” explained Professor Soljacic.

Source: BBC News
Further Reading: http://physicsweb.org/articles/news/11/6/5/1?rss=2.0

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3 Comments

  1. Adam June 14, 2007

    Wow, that is amazing. I would love getting rid of power cables!

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  3. Anthony September 7, 2007

    Didn’t Tesla come up with this over half a century ago?

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  5. Nightwriter December 6, 2007

    Tesla did do this, in 1899 at a much higher efficiency.

    Project Tesla
    The Wireless Transmission of Electrical Energy Using Schumann Resonance

    It has been proven that electrical energy can be propagated around the world between the surface of the Earth and the ionosphere at extreme low frequencies in what is known as the Schumann Cavity. The Schumann cavity surrounds the Earth between ground level and extends upward to a maximum 80 kilometers. Experiments to date have shown that electromagnetic waves of extreme low frequencies in the range of 8 Hz, the fundamental Schumann Resonance frequency, propagate with little attenuation around the planet within the Schumann Cavity.

    Knowing that a resonant cavity can be excited and that power can be delivered to that cavity similar to the methods used in microwave ovens for home use, it should be possible to resonate and deliver power via the Schumann Cavity to any point on Earth. This will result in practical wireless transmission of electrical power.

    From http://www.geocities.com/Area51/Shadowlands/9654/tesla/projecttesla.html

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