Published on December 13th, 2012 | by Nicholas Brown1
Magnetic Metamaterials Could Lead To Wireless Power Transmission
December 13th, 2012 by Nicholas Brown
The concept of transmitting electricity wirelessly to electric vehicles has dream-like advantages, and researchers from Spain say they have an idea that will make this a useful reality.
Probably the most idealistic dream related to such technology is that it would allow electric vehicles without energy storage systems. Electric vehicles without energy storage systems, such as trains, can be extremely fast, extremely efficient, and the cheapest overall, provided that the electricity transmission system is economical and efficient.
Electric vehicles without batteries would have an unparalleled power to weight ratio (their motors easily weigh less than 100 pounds). And their light weight would provide major handling and safety benefits. These benefits include shorter braking distance, lessened likelihood of rollovers, reduced likelihood of being rear-ended or rear-ending someone (since you will be better able to stop in time before slamming into the person in front of you). Another major benefit is the efficiency improvement gained from reduced weight. Weight is that important!
Finally, an advantage that isn’t weight related: the cost of replacing batteries would be eliminated.
Apart from that, wireless power transmission, even if short range, provides the benefit of charging short-range vehicle batteries along the road to extend their range.
The New Magnetic Metamaterial Concept
Physicists from Spain calculated that large amounts of energy can be transmitted via electromagnetism using certain materials.
The materials are called magnetic metamaterials. Metamaterials are artificial materials which are engineered to achieve certain properties that naturally occurring materials cannot achieve.
The effort to transmit electricity wirelessly goes back even to 1891, when Nikola Tesla transmitted it through the air using induction coils.
This concept builds upon the old concept of using electromagnetic induction to transmit electricity over short distances (in the same room).
According to Physics World:
“This is done using metamaterials with special optical properties that transform space in much the same way as the presence of mass deforms space – as described in Einstein’s general theory of relativity.
“In the case of an invisibility cloak, electromagnetic waves can be made to move smoothly around an object, joining up on the other side as if the object wasn’t there.”
New technologies usually have caveats, though:
“So far, so good – however there is one important caveat. Strictly speaking, the analysis only applies to static magnetic fields. To transfer the energy of an electric current by creating a magnetic field – and then extract the energy as an electric current at the other end – would involve a magnetic field that changes with time.”
We’ll see where this heads. Clearly, it’s still in a very early research phase.
Image Credit: Alvar Sanchez and colleagues
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