Posted on 03/11/2009 5:30:26 PM PDT by decimon
His discovery is a 'proof of principle' of the existence of a 'spin battery'
CORAL GABLES, FL. (March 11, 2009)—Researchers at the University of Miami and at the Universities of Tokyo and Tohoku, Japan, have been able to prove the existence of a "spin battery," a battery that is "charged" by applying a large magnetic field to nano-magnets in a device called a magnetic tunnel junction (MTJ). The new technology is a step towards the creation of computer hard drives with no moving parts, which would be much faster, less expensive and use less energy than current ones. In the future, the new battery could be developed to power cars. The study will be published in an upcoming issue of Nature and is available in an online advance publication of the journal.
The device created by University of Miami Physicist Stewart E. Barnes, of the College of Arts and Sciences and his collaborators can store energy in magnets rather than through chemical reactions. Like a winding up toy car, the spin battery is "wound up" by applying a large magnetic field --no chemistry involved. The device is potentially better than anything found so far, said Barnes.
"We had anticipated the effect, but the device produced a voltage over a hundred times too big and for tens of minutes, rather than for milliseconds as we had expected," Barnes said. "That this was counterintuitive is what lead to our theoretical understanding of what was really going on."
The secret behind this technology is the use of nano-magnets to induce an electromotive force. It uses the same principles as those in a conventional battery, except in a more direct fashion. The energy stored in a battery, be it in an iPod or an electric car, is in the form of chemical energy. When something is turned "on" there is a chemical reaction which occurs and produces an electric current. The new technology converts the magnetic energy directly into electrical energy, without a chemical reaction. The electrical current made in this process is called a spin polarized current and finds use in a new technology called "spintronics."
The new discovery advances our understanding of the way magnets work and its immediate application is to use the MTJs as electronic elements which work in different ways to conventional transistors. Although the actual device has a diameter about that of a human hair and cannot even light up an LED (light-emitting diode--a light source used as electronic component), the energy that might be stored in this way could potentially run a car for miles. The possibilities are endless, Barnes said.
"There are magnets hidden away in many things, for example there are several in a mobile telephone, many in a car, and they are what keeps your refrigerator closed," he said. "There are so many that even a small change in the way we understand of how they work, and which might lead to only a very small improvement in future machines, has a significant financial and energetic impact."
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To read the study log on to: http://www.nature.com/nature/index.html under "Advance Online Publication."
The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of the diversity of our University family, we strive to develop future leaders of our nation and the world. www.miami.edu.
Sounds interesting. What happens to a nano-magnet when it gets shocked. To use the articles example, drop your Ipod?
SSD’s - being flashed based - are slow compared to the speed of most circuits. The memory in my nVidia GTX 260 can be accessed at 111.9 Gigabytes per second - the fastest SSD peaks at 0.3 Gigabytes per second.
Somehow I’m not seeing the connection between a new kind of battery and a computer hard drive with no moving parts.
Different technology. The article doesn't say what is the magnetic material.
The article doesn't say how this would be used as a memory storage device. I guess the battery could be used to power, perhaps, solid-state storage or maybe the magnetic charge would be the storage. But I don't know.
Here is a PDF about making and characterizing MnAs nanostructures:
Fabrication and Characterization of MnAs/GaAs Heterostructures
for Studies of One-Dimensional Spin Transport
David Toyli
Physics, University of Minnesota
http://www.nnin.org/doc/NNINreu06Toyli.pdf
Direct large scale conversion of magnetic energy to electricity with no moving parts and no chemical reactions would definitely qualify as “Hugh and Series”...
Spin dizzies.
cities in space...
Like, *PING*, dudes.
This means we should eventually be able to replace rechargeable batteries that leak acid, with rechargeable magnets that leak electricity, with a potentially much higher energy density and recharge cycle life.
This would be a Jetsons level leap forward.
“We had anticipated the effect, but the device produced a voltage over a hundred times too big and for tens of minutes, rather than for milliseconds as we had expected,” Barnes said. “That this was counterintuitive is what lead to our theoretical understanding of what was really going on.”
That’s “led,” Brainiac.
bump for later read
Thanks for the PING. The article looks really interesting, unfortunately you can only get a bit more from the advance pub on the website than you do from this teaser. The nano-magnets are on the order of tens of atoms in diameter. Wow. Kewl.
Interesting technology discovery, but, as usual, the reporter is a boob. If no chemical reaction takes place to extract the energy, then it isn't stored as chemical energy.
It's really interesting how "different" familiar things turn out to be on the nano scale. Familiar devices given drastically improved performance (solar cells, solid oxide fuel cells, and now a new magnetic storage device).
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