The end of the plug? Scientists invent wireless device that beams electricity through your home

 

by DAVID DERBYSHIRE - More by this author » Last updated at 19:46pm on 7th June 2007 Comments

Dr Marin Soljacic : the inspiration behind the new wireless device

 

 

 

Scientists have sounded the death knell for the plug and power lead.

In a breakthrough that sounds like something out of Star Trek, researchers have discovered a way of "beaming" power across a room into light bulb, mobile phone or laptop computer without the need for wires or cables.

In the first experiment of its kind, the team was able to illuminate a 60 watt light bulb placed seven feet away.

The team from Massachusetts Institute of Technology, who describe their invention as "WiTricity", believe it could change they way we use electricity and do away with the tangle of cables, plugs and chargers that clutter up modern homes.

It could also allow people to operate laptops and mobile phones without batteries.

The inspiration came when the lead researcher, Dr Marin Soljacic was standing in his kitchen at night staring at his mobile phone.

"It was probably the sixth time that month that I was awakened by my cell phone beeping to let me know that I had forgotten to charge it.

"It occurred to me that it would be so great if the thing took care of its own charging," he said.

To turn this dream into reality, Dr Soljacic needed a way of transmitting power wirelessly.

Scientists have known for nearly two centuries that it is possible to transfer an electrical current from one coil of wire to another without them touching.

The phenomenon, known to physicists as electromagnetic induction, is used in billions of power transformers and electric motors around the world.

However, the coils in motors and transformers have to close for power to pass from one to another.

Attempting to transfer power over distances is impossible.

The breakthrough came when Dr Soljacic realised there was another way of transferring energy through the air.

Rather than sending power from a transmitter to a receiver as a conventional electromagnetic wave - the same form of radiation as light, radio waves and microwaves - he could use the transmitter to fill a room with a "non-radiative" electromagnetic field.

Most objects in the room - such as people, desks, carpets and passing pets - would be unaffected by the electromagnetic field.

But any objects designed to resonate with the electromagnetic field would absorb the energy.

It sounds complicated, but the result – demonstrated by the American team this month – was a dramatic success.

Using two coils of copper, the team transmitted power seven feet through the air to a light bulb. The bulb lit up instantly.

The scientists say the technique works only over distances of up to nine feet.

However, they believe it could be used to charge up a battery within a few yards of the power source connected to a receiving coil.

Placing one source in each room could provide enough power for an entire house.

The receiver and transmitter would not have to be in view of each other.

Prof Peter Fisher, another of the researchers, said: "As long as the laptop is in a room equipped with a source of wireless power, it would charge automatically without having to be plugged in.

"In fact, it would not even need a battery to operate inside of such a room.".

The researchers say there is little to worry about on safety grounds.

Magnetic fields interact weakly with living organisms and are unlikely to have any serious side effects, the team say.

Dr Soljacic predicts that power cables and chargers could soon become a thing of the past.

"Once, when my son was about three years old, we visited his grandparents' house," he said.

"They had a 20 year old phone and my son picked up the handset asking 'Dad, why is this phone attached with a cord to the wall?'.

"That is the mindset of a child growing up in a wireless world. My best response was, it is strange and awkward isn't it.

"Hopefully we will be getting rid of some more wires, and also batteries, soon."

great. We'll have charged up mobile phones and fried brains. Sounds like fun :rolleyes:

great. We'll have charged up mobile phones and fried brains. Sounds like fun :rolleyes:

 

Beam me up, Watty??:rolleyes:

Yeah, I actually remember taking part in an on the street survey about this in London.....and that was 3 years ago!

 

I really didn't like the idea too much - it's really exciting - but I just do not 100% trust wireless anything when it comes to health issues.

 

There are more bad than good reports that say there’s evidence of wireless signals/waves causing all sorts of health risks. (I mean even iPods can cause pacemakers to malfunction)

 

And if you read the reports that state "there's no risk" then you should pay close attention because they also say that there is no way of knowing for sure because the technology has not been widely used for long enough. And those reports are mostly funded by the companies who are benefiting from the technology.

Thanks for the offer, but no thanks, I don't want my body to get electricity running though it.