Fun With Pseudofluids

December 22, 2004 4:29 PM

You probably knew that Silly Putty is a non-Newtonian fluid, and that Faraday waves make cornstarch and water do creepy things, but did you know that your washing machine probably has magnetorheological fluid in it? Yes indeed, there are fun and interesting applications for ferrofluids.
posted by Specklet (20 comments total)

This magnetorheological fluid--it doesn't vibrate?
posted by weapons-grade pandemonium at 4:44 PM on December 22, 2004

I love stuff like this, the cornstarch video and the ferrofluid video are both especially great. My next ferrofluid purchase will probably be magnetic paint, since I rent an apartment with fragile plaster walls that do not take kindly to nails. Magnets are awesome.
posted by cali at 5:45 PM on December 22, 2004

Interesting. Now I'm going to have to disassemble my front-loading washer and find out if it's using conventional shock absorbers, or magnetorheological ones. I hope it's the latter!
posted by five fresh fish at 5:57 PM on December 22, 2004

This is awesome. I want some of that paint, cali.

I must say that although dinosaurs, the Ninja Turtles, and Santa Claus have lost much of their luster since I discovered them in my childhood, magnets are still fucking cool as hell.
posted by Embryo at 5:59 PM on December 22, 2004

wow. cool, thanks. tomorrow i'll be checking to see if the dampers on our washing machine have wires attached....
posted by andrew cooke at 6:00 PM on December 22, 2004

thanks! they found negative normal stress in mayonnaise btw :D
posted by kliuless at 6:14 PM on December 22, 2004

I did not know that. Now I do.

The cornstarch-and-water video, particularly the fingers at the end, is what the ocean in Solaris has always looked like in my mind's eye.

I wonder how many orders "Educational Innovations" is going to get for bottles of Ferrofluid.
posted by Wolfdog at 6:19 PM on December 22, 2004

Wow. magnetic paint.... I wonder if you could paint a wifi antenna?

Great links.
posted by Freen at 6:22 PM on December 22, 2004

Great set of links on a fascinating topic. One other area needs mentioning MagnetoRheological fluid Optimized Active Damper Suspensions.
posted by DV8 2XL at 6:24 PM on December 22, 2004

DV8, GM has actually offered their MagneRide suspension on certain cars since 2001.
posted by esoterica at 6:54 PM on December 22, 2004

Another fascinating article from The Economist about the potential commercial uses of "Smart Fluid," in everything from digital cameras to artificial limbs to automatic clutches.
posted by esoterica at 7:08 PM on December 22, 2004

For the scientifically minded, check out the work of Trevor Douglas at Montana State University. He is creating miniature magnetic particles of various sizes by mineralizing the interior of various hollow nano-scale biological containers (ferritin, heat shock proteins, virus capsids).
posted by 445supermag at 7:28 PM on December 22, 2004

Of related interest, Army creates liquid armor. This one's about composites of Kevlar with shear-thickening fluids, that temporarily harden on impact.
posted by raygirvan at 7:35 PM on December 22, 2004

I tried to buy some magnetic paint the other day, but my Mastercard wouldn't swipe.
posted by weapons-grade pandemonium at 9:01 PM on December 22, 2004

Thank you, Speklet. Now I can say I learned something today.
posted by raedyn at 9:53 PM on December 22, 2004

Sweet. I did my Gr. 11 science expo project on Magnetoheological fluids (thanks a bunch Scientific American!). Got me 85% for it, yes indeed.
posted by PenDevil at 11:36 PM on December 22, 2004

Speaking of Silly Putty...everyone here knows how to make it ya? Super simple joining of polymers...specifically Polyvinyl Acetate...what makes white glue sticky ! To join it, you need Sodium Tetraborate...in other words, Borax soap.

The Borax needs to be in solution...80g/Gallon. Put your white glue (it doesnt have to be Elmers!) in a container you dont care about, add a couple drops of food coloring, stir it up. Layer on the Sodium Borate solution and stir stir stir! It *very* quickly starts to glom together, so do everything you can to work it...add more Borate solution on top as needed. Eventually, it will not be sticky anymore, so take it out of its container and put it in your hand over a garbage can. Keep working it in your hand as you drizzle more Borate solution on top and voila, homebrew Silly Putty.

Do note, you can even add a drop of scented oil to the glue beforehand....and its best if you store it in some borate solution. This is the same putty you get when you buy Silly brand (same stretch/shear/pick up newsprint properties :) If you can get your hands on Polyvinyl Alcohol, put it in solution (112g/Gallon), color or scent as before, mix with Sodium Borate (~10:1 ratio PVA:SB) and you have slime! (I do this pretty much everyday at work..tho yesterday I was playing with drops of food coloring in whole milk and soap).
posted by gren at 5:41 AM on December 23, 2004

Wow, thanks for all the links in return, guys!
posted by Specklet at 9:04 AM on December 23, 2004

The trick to the washing machine is that its dampers consist simply of six hydrocoptic marzel-vanes, so fitted to the ambifasciant lunar wane shaft so that side fumbling is effectively prevented.
posted by jewzilla at 11:02 AM on December 23, 2004

Thank you jewzilla, that made my day.
posted by FissionChips at 3:41 PM on December 23, 2004