Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Kind of MRI Enables Study of Magnets for Computer Memory

17.07.2008
What is there to see inside a magnet that's smaller than the head of a pin?

Quite a lot, say physicists who've invented a new kind of MRI technique to do just that.

The technique may eventually enable the development of extremely small computers, and even give doctors a new tool for studying the plaques in blood vessels that play a role in diseases such as heart disease.

In a recent issue of Physical Review Letters, the scientists report the first-ever magnetic resonance image of the inside of an extremely tiny magnet.

Specifically, the magnet is a "ferromagnet" -- a magnet made of ferrous metal such as iron. It's what most people think of when they hear the word "magnet."

"The magnets we study are basically the same as a refrigerator magnet, only much smaller," said project leader Chris Hammel, Ohio Eminent Scholar in Experimental Physics at Ohio State University. The disk-shaped magnets in this study measured only two micrometers (millionths of a meter) across.

"Because ferromagnets generate such strong magnetic fields, we can't study them with typical MRI. A related technique, ferromagnetic resonance, or FMR, would work, but it's not sensitive enough to study individual magnets that are this small."

Likewise, medical researchers can't use MRI to image plaques formed in the body, because plaques are too small. That's why this new kind of magnetic resonance could eventually become a tool for biomedical research.

The technique combines three different kinds of technology: MRI, FMR, and atomic force microscopy.

They dubbed the technique "scanned probe ferromagnetic resonance force microscopy," or scanned probe FMRFM, and it involves detecting a magnetic signal using a tiny silicon bar with an even tinier magnetic probe on its tip.

As the probe passes over a material, it captures a bowl-shaped image: a curved cross-section of an object. The magnetic signal is more intense in the middle (the "bottom" of the bowl), and fades away toward the edges.

It may sound like an odd configuration, but that's why the new technique works.

Every atom emits radio waves at a particular frequency. But to know where those atoms are, scientists need to be able to localize where the radio waves are coming from.

Large-scale MRI machines, such as those in hospitals, get around this problem by varying the magnetic field by precise amounts as it sweeps over an object. The computer controlling the MRI knows that where the magnetic field equals X, the location equals Y. Sophisticated software combines the data, and doctors get a 3D view inside a patient's body.

For Hammel's tiny magnets, no methods were previously known that would image the inside of them, much less allow for precise localization. But since the new probe system generates a magnetic field that varies naturally, the physicists discovered that they could sweep the probe over an array of magnets and get a 2D view that's similar to a medical MRI. In Physical Review Letters, they reported an image resolution of 250 nanometers (billionths of a meter).

Now that they have their imaging technique, Hammel and his team are beginning to record the properties of many different kinds of tiny magnets -- a critical first step toward developing them for computer memory.

Experts believe that one day, tiny magnets could be implanted on a computer's central processing unit (CPU) chip. Because system data could be recorded on the magnets, such a computer would never need to boot up. It would also be very small; essentially, the entire computer would be contained in the CPU.

For biomedical research, the technique could be used to study tissue samples taken from plaques that form in brain tissues and arteries in the body. Many diseases are associated with plaques, including Alzheimer's and atherosclerosis. Currently, researchers are trying to study the structure of plaques in detail to understand how they form and how they affect conventional MRI images.

Hammel and his team hope to contribute to the development of an instrument that could be sold and used routinely in laboratories. But the technique needs some further development before it could become an everyday tool for the computer industry or for biomedicine.

Hammel's Ohio State coauthors on the paper include Yuri Obukhov, a research associate; Thomas Gramila, associate professor of physics; Denis Pelekhov, a research scientist in the university's Institute for Materials Research; Palash Banerjee, a postdoctoral researcher; and Jongjoo Kim and Sanghun An, both doctoral students. They collaborated with Ivar Martin, Evgueni Nazaretski and Roman Movshovich of Los Alamos National Laboratory; and Sharat Batra of Seagate Research, the research and development center of hard drive manufacturer Seagate Technologies.

This work was funded by the Department of Energy.

Contact: P. Chris Hammel, (614) 247-6928; Hammel.7@osu.edu

Pam Frost Gorder | Newswise Science News
Further information:
http://www.osu.edu

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>