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"Spin Battery" Effect Discovered

Posted by kdawson on from the usual-caveats-apply dept.

An anonymous reader writes "Researchers at the University of Miami and at the Universities of Tokyo and Tohoku, in Japan, have discovered a spin battery effect: the ability to store energy into the magnetic spin of a material and to later extract that energy as electricity, without a chemical reaction. The researchers have built an actual device to demonstrate the effect that has a diameter about that of a human hair. This is a potentially game-changing discovery that could affect battery and other technologies. Quoting: Although the actual device... cannot even light up an LED..., the energy that might be stored in this way could potentially run a car for miles. The possibilities are endless, Barnes said.'"

5 of 234 comments (clear)

  1. Can't light an LED by Taibhsear · · Score: 4, Interesting

    Is this due to the scale of the device/experiment or is it a limitation in the output that they can get it to generate so far?

    1. Re:Can't light an LED by Anonymous Coward · · Score: 4, Interesting

      Well the device they've built has the diameter of a human hair it doesn't really matter (unless it's also really really long). Ten thousand in a battery the size of a AA would surely give off more energy than existing alkali or NiMH batteries of the same size.

    2. Re:Can't light an LED by BillOfThePecosKind · · Score: 4, Interesting

      I would think it would be a limitation of the test size. If it's like any other electrical device, we should be able to stack a WHOLE bunch of them in series to create larger voltages. I really hope this goes somewhere, a lot of what is holding us back from implementing more renewable energy sources is the fact that we have no efficient (cost efficient mostly) way of storing the energy.

    3. Re:Can't light an LED by Chyeld · · Score: 4, Interesting

      More importantly, you can stack several chemical batteries together for more power and the only issue you have to worry about is heat.

      Stack several magnetic based batteries together, are you going to have to worry about their fields interfering with each other? What if this is only a workable model when the battery IS the width of a human hair.

  2. Static magnetic field? by Wilson_6500 · · Score: 3, Interesting

    Spintronics is a little too far out of my ken (I was always more of a radiation physicist, where everything comes in nice little packages instead of fields), but if I'm reading the paper correctly, they're saying that they can apply a static magnetic field to one of these devices and then can measure a voltage drop across a resistor hooked up to the device. They can get a few millivolts from a 1.2 Tesla field, which persists for at least ten minutes but does decay in that time frame. When they remove the magnetic field, the voltage disappears.

    I guess my question is that if the field is static, where is the energy coming from that drives the current giving rise to the voltage? I'm also wondering how one regenerates the voltage after it discharges completely.