Look ma, no hands: Engineers invent a magnetic fluid pump with no moving parts

Sep 16, 2011 By Karen N. Peart
Hur Koser, who found a way to pump ferrofluids by magnetic fields alone, holds a sample.

(PhysOrg.com) -- Used in Hollywood and the advertising industry to create exotic special effects, ferrofluids are seemingly magical materials that are both liquid and magnetic at once. In a study published today in Physical Review B, Yale electrical engineering professor Hur Koser and colleagues from the University of Georgia and Massachusetts Institute of Technology demonstrate for the first time an approach that allows ferrofluids to be pumped by magnetic fields alone. The invention could lead to new applications for this mysterious material.

Developed in the 1960s by NASA scientists seeking a non-mechanical method for moving in outer space, ferrofluids are made up of magnetic nanoparticles suspended in liquids such as oil, water, or alcohol. Though numerous industrial, commercial, and for ferrofluids have since been created, the original goal-to pump with no machinery-remained elusive, until now.

"We have shown that ferrofluids may be pumped at controllable speeds in closed-loop geometries without any mechanically moving parts," says Koser. The discovery, based on work funded in part by the National Science Foundation, is a culmination of many years of research, and is based on a theory Koser proposed in 2005 to suggest that travelling magnetic fields could enable very fast pumping of ferrofluids.

Following on successful computational simulations, the so-called "ferrohydrodynamic pumping mechanism" that Koser and colleagues have now validated could be used in systems as tiny as , or as large as industrial-scale pumps, he says. It could also be used to cool computers more efficiently.

The ferrohydrodynamic pump method works when electrodes wound around a pipe force within the ferrofluids to rotate at varying speeds.  Those particles closest to the spin faster, and it is this spatial variation in rotation speed that propels the ferrofluid forward. "We don't rely on any other material; no magnets, nothing moving but the ferrofluid that we're pumping," Koser says.

Koser and colleagues demonstrated the simplicity of this "hands-free" pumping scheme using a stereo amplifier, ordinary plumbing materials from the local hardware store, and a commercially available mineral oil/magnetite ferrofluid that is easy to make and safe to handle. "Pumping systems can be much cheaper and easier to manufacture when liquid can be moved without machinery," Koser notes.

"The ferrofluid pumping scheme we demonstrated is simple, robust, and very inexpensive," says co-author Leidong Mao, a former graduate student in Koser's lab, currently with the Faculty of Engineering at the University of Georgia. Their approach, Mao notes, could lead to highly compact, integrated, quiet, and efficient liquid cooling schemes for portable, high-performance consumer electronics. For instance, ferrofluid cooling would eliminate the need for fans and heat plumbing inside computers, enabling further miniaturization. "Your laptop could be twice as thin and a third lighter and faster with more efficient cooling," Koser says. Novel medical applications, such as cell sorting, might also be enabled by biocompatible ferrofluids, he adds.

Other co-authors include Shihab Elborai, Xiaowei He, and Markus Zahn from MIT's Laboratory for Electromagnetic and Electronic Systems. To read the paper, Direct observation of closed-loop ferrohydrodynamic pumping under traveling magnetic fields, see the current issue of Physical Review B.

Explore further: Physical constant is constant even in strong gravitational fields

More information: prb.aps.org/abstract/PRB/v84/i10/e104431

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User comments : 12

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Isaacsname
4 / 5 (5) Sep 16, 2011
.....I have a suggestion.

Can Physorg perhaps negotiate a deal to allow a registered member to read these papers without having to pay ? It could be open for temporary viewing within the first few days of the article/press release.

..starting to seem like spam in a sense.

* Wanted to add my suggestion for the newest big word in science: ferromagnetofluidhydrodynamics
rift321
2 / 5 (2) Sep 16, 2011
Would it be possible to suspend ferromagnetic nanoparticles in air, and control their spin using electrodes in the same fashion?

It would be nice to have fans with zero moving parts!
XQuantumKnightX
2 / 5 (5) Sep 16, 2011
We could use this technology to create an artificial heart by placing ferromagnectic nano particles in the blood stream and add this pump in the heart. I just want 15% for this documented ideal!
XQuantumKnightX
not rated yet Sep 16, 2011
We also can use this to control cellular movement throughout the body. For instance, stem cells and Tcells.
Yevgen
not rated yet Sep 16, 2011
Would it be possible to suspend ferromagnetic nanoparticles in air, and control their spin using electrodes in the same fashion?

It would be nice to have fans with zero moving parts!


This is already possible by using ionic drift in the air during
corona discharge. People used the effect to make levitating devices called "lifter". Same method could also be used in
liquids.
See details here: http://sudy_zhenja.tripod.com/lifter_theory/
One issue is efficiency. Regular fans are still more efficient
than corona discharge fans. I wonder how the energy efficiency
of their pump compares to traditional mechanical pumps?
thales
5 / 5 (3) Sep 16, 2011
We could use this technology to create an artificial heart by placing ferromagnectic nano particles in the blood stream and add this pump in the heart. I just want 15% for this documented ideal!


There are already ferromagnetic nano particles in the blood stream.
XQuantumKnightX
not rated yet Sep 16, 2011
We could use this technology to create an artificial heart by placing ferromagnectic nano particles in the blood stream and add this pump in the heart. I just want 15% for this documented ideal!


There are already ferromagnetic nano particles in the blood stream.


I agree that there are ferromagnetic nano particles in the blood stream already being used for other medical purposes. I am saying that we can keep our blood pumping with this same technology, which is not being done today. This is why I want my 15% of the profits. Check this out FMI: http://authors.li...u/22046/
Vendicar_Decarian
1 / 5 (1) Sep 16, 2011
damn good idea.
Rohitasch
not rated yet Sep 16, 2011
This could mean the end of constipation!
CHollman82
5 / 5 (3) Sep 16, 2011
We could use this technology to create an artificial heart by placing ferromagnectic nano particles in the blood stream and add this pump in the heart. I just want 15% for this documented ideal!


There are already ferromagnetic nano particles in the blood stream.


Yeah, iron...
MaxwellsDemon
5 / 5 (2) Sep 17, 2011
Iron doesn't exhibit ferromagnetism unless it's aggregated at the molecular level. Which is why people don't explode in MRI machines. http://www.revise...raction/
Wolf358
not rated yet Sep 17, 2011
So long as the oil component of the FMF didn't contaminate the working fluid, a peristaltic pump would be pretty simple...