Pumping Fluid With No Moving Parts 75
RogerRoast writes "In a study published in Physical Review B (abstract; full version is paywalled), researchers 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. Though numerous industrial, commercial, and biomedical applications for ferrofluids have since been created, the original goal — to pump liquids with no machinery — remained elusive, until now. The ferrohydrodynamic pump method works when electrodes wound around a pipe force magnetic nanoparticles within the ferrofluids to rotate at varying speeds. Those particles closest to the electrodes spin faster, and it is this spatial variation in rotation speed that propels the ferrofluid forward."
An evolution from magnetohydrodynamics... (Score:4, Informative)
Magnetohydrodynamics [wikipedia.org] has been around for quite a while and has long been one of the holy grails of submarine propulsion with prototypes existing now for years. During my last visit to a Los Angeles class submarine [utah.edu], this was a hot topic. Movement of ferrofluids is a natural extension of this concept with applications in everything from medical imaging to cooling of large and small objects. Its pretty exciting, though I am surprised that this is the *first* implementation of this.
Re:Interesting to see a macro-scale solution (Score:5, Informative)
(Sorry for gloating, I *finally* got access to journals again and it is SO EXCITING. I have no life.)
Right, according to the article, the reason people have looked at ferrofluids for microfluidics is that they were interested in using a thin layer of ferrofluid to drive a plug of other liquid. This would be analogous to the ionic double-layer (Debye layer) in electro-osmosis, as mentioned above. In this experiment, they use only ferrofluid (with a dash of a tracer) and seem to achieve a funky toroidal region, leading to ordinary laminar flow. If they excited it in more places then they could have a lot of mixing, which would be great for a cooling system.
Pumping without moving parts is not news. (Score:2, Informative)
Pumping without moving parts is not news. Liquid metal cooled nuclear reactors, aluminium foundries use this technology, among other things.
Not rocket science, you can go buy yourself a magnetic metal "pump" today: http://www.cminovacast.com/prod/index.html (google 1st for liquid metal cooling pump).
Oh, you talk about magnetically pumping non-metals. Well that's nice.