
A Permanently Magnetic Liquid - amingilani
https://www.sciencealert.com/scientists-have-printed-droplets-of-permanently-magnetic-liquid-and-boy-is-it-trippy
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userbinator
_" Before our study, people always assumed that permanent magnets could only
be made from solids."_

If you finely divide a magnet into tiny magnets and suspend these particles in
a liquid, is that really a liquid magnet, or just a bunch of solid magnets
floating in a liquid?

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liuhenry
You've actually stumbled upon the central premise of this discovery.

If you finely divide a magnet into tiny magnets and suspend the particles in a
liquid, you get... a normal ferrofluid. It's magnetic in the presence of an
external field, but will lose its magnetization once that field is removed.
This is because permanent magnetism (i.e. ferromagnetism) _is a bulk
property_.

Every atom has a magnetic moment, but they are normally randomly aligned and
thus the macroscopic field cancels out. It's only when these moments are
aligned that a macroscopic magnetic field arises. Permanent magnets have the
requisite crystalline structure for this to happen. As you chop it up, this
macroscopic organization is destroyed.

If you get into the details, what they've done is to use the surface tension
of the oil-in-water to "jam" an outer layer of magnetic particles and prevent
them from rotating, thus preserving their magnetic alignment. This, in turn,
is apparently enough to keep the free-floating, unjammed particles inside the
droplet aligned as well, thus turning the entire droplet into a magnet. Pretty
interesting, because without the membrane, none of the ferrofluid is magnetic,
but with the membrane, all of it is.

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Zanni
This is a better explanation than the original article.

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inmate4587
I second that

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pontifier
This may be useful in actually creating something I theorized about a few
months ago. I call it a chemomagnet (as opposed to electromagnet).

The basic premise is that individual magnetic domains are free to float and
are unorganized until a chemical signal locks them into place in some sort of
structure. The energy required to align and bind them would be chemical in
nature, and once bound, another chemical signal could be sent to unbind them.

The magnet would be controllable, like an electromagnet, but would not require
any electricity at all to operate.

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GistNoesis
Isn't a chemomagnet magnet just a scaled down version of a mechanical
switchable magnet?

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yetihehe
Yeah, but you could program it with any number and position of magnetic poles.
Imagine a ring of this material as a stator in electric motor, you could
reprogram it with 4 or 6 poles on the fly.

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dustfinger
liquid programable motors with possible temporal formation capabilities!
Sounds one step closer to Skynet's liquid metal terminator :-)

Fascinating!

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exebook
Is it possible now to make a completely silent water/magnetic liquid cooler
for a CPU by forcing this liquid to flow inside a heat pipe by a few
electromagnets? Thus removing the noisy motor driven pump.

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dhosek
Great. Now we're one step closer to the T-1000.

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timemachine
Came to make the same comment.

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bryanrasmussen
I figure Skynet probably sent back an editorbot to flag your comment if you
succeeded, but you tried your best to alter the future. John would be proud.

