posted on Jan, 8 2013 @ 02:30 PM
As indicated in earlier studies and as observed
in Nature, it is indeed
possible to transfer magnetic energy from one point to another through a non-magnetic medium or empty space.
A general property of magnetic fields is that they decay with the distance from their magnetic source. But in a new study, physicists have shown
that surrounding a magnetic source with a magnetic shell can enhance the magnetic field as it moves away from the source, allowing magnetic energy to
be transferred to a distant location through empty space.
By reversing this technique, the scientists showed that the transferred magnetic energy can be captured by a second magnetic shell located some
distance away from the first shell. The second shell can then concentrate the captured magnetic energy into a small interior region. The achievement
represents an unprecedented ability to transport and concentrate magnetic energy, and could have applications in the wireless transmission of energy,
medical techniques, and other areas.
The way how scientists from the Autonomous University of Barcelona were able to manipulate magnetic fields is remarkable. Enhancement, transfer,
concentration and capture, all with an experimental set up that is rather simple.
[The newly designed magnetic shell can either expel or concentrate magnetic energy. In the left panels, a small dipole magnet in (a) is surrounded by
a magnetic shell in (b), which expels its magnetic energy further outward. In (c), a second shell harvests the energy and concentrates it into its
center hole; in this way, magnetic energy is transferred through empty space. In the right panels, two dipole magnets in (d) are surrounded by shells
in (e) that expel their magnetic energy. As shown in (f), the result is magnetic coupling between the two dipoles.]
[Magnetic shells can be used to increase the magnetic energy of multiple magnets: The four magnetic dipoles in (a) interact very weakly, even when
they are moved closer together in (b). However, when all four dipoles are surrounded by a shell as in (c), their exterior fields become enhanced,
yielding a stronger magnetic field in the center region.]
- Credit: Carles Navau, et al. ©2012 American Physical Society
Magnetic energy is one the main agents powering our society: generating energy in power plants, keeping information in magnetic memories, moving
our devices with motors. All of these applications require a certain spatial distribution of magnetic energy, for example concentrating it in a
transformer core or in a magnetic sensor.
We introduce in this work a way to collect magnetic energy and distribute it in space with unprecedented efficiency and flexibility, allowing very
large concentration of magnetic energy in a free space region, an enhanced magnetic coupling between two magnetic sources, and the transfer of
magnetic energy from a source to a given distant point separated by empty space.
All these features are achieved with a single device, a magnetic shell designed by transformation optics.
Magnetic energy harvesting