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Offline realmswalker

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Liquid magnet
« on: 18/05/2006 23:48:49 »
I am a bit of an amateur at magnetics, but i was wondering, is there any liquid that can be magnetically charged, or at least be affected or contained by magenets


 

another_someone

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Re: Liquid magnet
« Reply #1 on: 19/05/2006 01:04:56 »
Don't know about liquid magnets in a literal sense, but you can get suspensions of magnetic particles in oil.  These are often used for liquid bearings, where the microscopic magnetic particles suspended in the oil are trapped within a magnetic field, preventing the oil itself from flowing out of the bearing.



George
 

Offline realmswalker

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Re: Liquid magnet
« Reply #2 on: 19/05/2006 03:50:09 »
hmmm, what stops a powerful magnet from drawing the particles out of suspension?
 

Offline Atomic-S

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Re: Liquid magnet
« Reply #3 on: 19/05/2006 06:21:40 »
I never heard of this before. It would be interesting to see a diagram of this device.
 

another_someone

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Re: Liquid magnet
« Reply #4 on: 19/05/2006 10:49:08 »
Sorry, my mistake they are seals not bearings.

http://en.wikipedia.org/wiki/Ferrofluid
quote:

A ferrofluid is a specific type of liquid which responds to a magnetic field. Ferrofluids are composed of nanoscale magnetic particles suspended in a carrier fluid. The solid particles are generally stabilized with an attached surfactant layer.


Applications


They are used in loudspeakers to sink heat between the voice coil and the magnet assembly, and to passively damp the movement of the cone. They reside in what would normally be the air gap around the voice coil, held in place by the speaker's magnet.
Ferrofluids are similarly used to form liquid seals around the spinning drive shafts in hard disks.
Using electromagnets and sensors, the viscosity of magnetorheological fluids can be controlled dynamically, allowing for active damping (in car shock absorbers like Delphi Corporation's MagnaRide, for instance). This allows hundreds of watts of mechanical power to be controlled with a few watts of electrical power, which is much more efficient than other methods of vibration control, such as piezoelectric crystals.
They also have friction-reducing capabilities as well. If applied to the surface of a strong enough magnet, such as one made of neodymium, it can glide across smooth surfaces with minimal resistance.





George
 

Offline neilep

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Re: Liquid magnet
« Reply #5 on: 19/05/2006 13:21:42 »
Still, a magebtic liquid does sound fascinating !...Could one heat up a magnet till it melts ?

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ROBERT

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Re: Liquid magnet
« Reply #6 on: 19/05/2006 14:54:30 »
quote:
Originally posted by neilep

Still, a magebtic liquid does sound fascinating !...Could one heat up a magnet till it melts ?

Men are the same as women, just inside out !



If you heat a magnet above its "Curie point" is loses its magnetism:-http://en.wikipedia.org/wiki/Curie_point
 

Offline neilep

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Re: Liquid magnet
« Reply #7 on: 19/05/2006 15:31:00 »
Thanks Robert.

Does ther magnetism return once the magnet cools ?....so where does the magnestism go ?

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ROBERT

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Re: Liquid magnet
« Reply #8 on: 19/05/2006 16:08:07 »
quote:
Originally posted by neilep

Thanks Robert.

Does ther magnetism return once the magnet cools ?....so where does the magnestism go ?



If the metal is not in a magnetic field, the magnetism will not return on cooling.
After heating the atoms have lost the alignment which caused the metal to be magnetic. Without alignment the magnetic force of each atom is randomly oriented and cancels out any net effect.


Here is a site which shows still and moving pictures of Ferrofluid in magnetic fields:-
http://www.dansdata.com/magnets.htm
When you go to the above site click on this video, its freaky, very T-1000.

 

« Last Edit: 19/05/2006 17:04:03 by ROBERT »
 

Offline neilep

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Re: Liquid magnet
« Reply #9 on: 19/05/2006 17:08:11 »
Woooo !!..that is indeed quite freaky !!...thanks Mr Robert.

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Offline realmswalker

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Re: Liquid magnet
« Reply #10 on: 20/05/2006 09:23:38 »
OMG that is perfect
i can do what i was hoping i can!
If you had a ring with VERY powerful magnets pointing towards the center of the ring, all the same pole (yeh theyd repel each other alot, but you can fight that) and you put that ferroliquid into it, if you had the magnets set right (slightly stronger ones on the top) you could have a wall of fluid that you could pass through, but wouldnt be visible through....i think. The very center would have influences of all the magnets (the way the feilds are shaped) and therefore you could make it so that it was equally attractive as the area closer to the magnets, if not more attractive.

This might not seem like much, but if it is a Magnetorheological fluid, which gets harder as more magnetic feild is applied, you could make a wall that could be turned on and off quite easily, or made semi permeable!
Doing more research i found there are the same type of thing, only with electrical current, and ones that are both....
I know my idea would work...
and It would be really cool....

ima design one, ill post what i design!
Thank you so much
« Last Edit: 20/05/2006 09:33:37 by realmswalker »
 

Offline neilep

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Re: Liquid magnet
« Reply #11 on: 21/05/2006 03:07:46 »
Is the liquid still flowing through that magnetic field ?...does the pattern contain streaming liquid ?..

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Offline Mr Andrew

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Re: Liquid magnet
« Reply #12 on: 05/06/2006 20:38:48 »
Hey, that's a great idea. I have a good one too. If you've ever read Ender's Game you'll appreciate this. You could make a flash suit with little hinges in the joints filled with a magnetorheological fluid and an electromagnet. When you got hit with the laser a photoelectric material could transfer the current to a generator that would turn on the electromagnet and freeze you in whatever position you are in!!! I have already begun research on these fluids in my chemistry class and it prove quite promising:D!!!!!!!

Oh man, I'm so excited just thinking about it!!!

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Offline Bladers

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Re: Liquid magnet
« Reply #13 on: 06/06/2006 18:05:33 »
A magnetorheological fluids, when pured onto a cup, if you put a magnet near it, it gets hard like a rock. when you remove the magnet it goes back to its liquid form. It can go from liquid to solid in less then .1 second (milisecond)-(10% of a second).

Or if you looking for a shear thickening fluid, when force is active fluid turns to solid. It means if you stab a ice pick right in the cup, before you get quarter of you way in the fluid it stops you right in your tracks.(shear thickening fluid), or if your turn the ice pick slowly in a circle motion, then instantly start turn rapidly. It will stop you instantly.
 

Offline Mr Andrew

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Re: Liquid magnet
« Reply #14 on: 06/06/2006 23:12:03 »
Oh man, that sounds interesting.

Shear thickening liquids, could you use it to make a liquid floor?  The floor can flow (and look really cool) but when you step on it it becomes solid! I love magnets!!!:D

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Offline Bladers

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Re: Liquid magnet
« Reply #15 on: 07/06/2006 14:49:34 »
Shear thickening liquids doesntt deal with any thing about magnet.
only magnetorheological do.
 

Offline Mr Andrew

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Re: Liquid magnet
« Reply #16 on: 07/06/2006 20:21:09 »
No kidding, I was remarking on the original topic of the thread.  It was the liquid magnet topic that brought us to the topic of sheer thinckening liquids anyway.

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Offline Bladers

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Re: Liquid magnet
« Reply #17 on: 08/06/2006 00:48:56 »
US Army are using it to make liquid body armors
 

Offline realmswalker

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Re: Liquid magnet
« Reply #18 on: 08/06/2006 03:02:58 »
I jsut did soem research:
http://flux.aps.org/meetings/YR97/BAPSMAR97/abs/S5460.html
there is a version of this that reacts to an electric current like magnetorheoulogical ones to to magnetic fields.

This is very intresting...
Now what if you had a powerful magnetic field in the shape of a dome?
Then from a helicopter dropped magnetorheuoulogical fluid on it...
Would it build the dome? Actually..i think youd have to apply the bottum parts first...or else it woudl jsut fall down lol
Idk...it seems you could use it for something like that, like portable  fluid buildings or something...
You could use the electric one in robotics, as long as an electric current flows through it its hard, but when it stops, it becomes liquid, or soft at least...i can see multiple applicaitons, from grasping hands, to joints that dont need many moving parts, just electrical curents...

or you could make a floor that was on off liquid, just apply eletrical current or magnets or pressure from teh bottum (depending on what it is made of) and you get a solid floor! Take it away, it goes to liquid!
It seems so cool!.
you could use it as a way to protect things, place it in a special container of this, and then you apply pressure, the liquid solidifies to a solid, completly protecting what ever is inside!

Or you could perhaps make a wheel that turned itself sort of (idk just thinking of aplications)
YOu have a large blob of perhaps magnetorheulogical fluid with a sphere in the middle, that has pwerful, horse shoe shaped (to make sure they face the same direction) magnets. By turning these electro magnets off, you could melt and resolidfy areas of the sphere, melt the front area, it becomes liquid and the whole thing rolls forward, then solidify it when it gets under it. I wonder if that would work...
To stop the fluid from being completley lost, you could turn the magnetic field off somewhat, resulting in a soft but not entirely liquid portion of the tire thing.


How hard does this stuff get? You perhaps could use it for bomb containment. Just roll one of these things over the bomb, and harden it!
Im sure if it were big enough, it would contain it!

I wonder what other "Smart fluids" are out there...
Are there any that contract or expand on the applicaiton of electric or magnetic fields/current?
This stuff seems so scifi!
I wonder if it is possible to mix the properties of these?
« Last Edit: 08/06/2006 03:27:38 by realmswalker »
 

Offline Mr Andrew

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Re: Liquid magnet
« Reply #19 on: 08/06/2006 20:32:58 »
Those are all great ideas, and very plausible...if only you could cheaply produce a strong enough magnetic field for that dome thing.
Also, the iron would possible rust, weakening the structure, but if you used steel, I wonder what would happen? Is steel still ferrous? How would metal objects inside the building respond? What if you could make a sort of solid that was malleable but would become rigid in a magnetic field? Sort of like play-doh but could be used to construct reshapable buildings. There seems to be endless possibilities!:D I see a completely new field of science evolving here.

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Offline realmswalker

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Re: Liquid magnet
« Reply #20 on: 08/06/2006 21:11:00 »
it already exists, i just was doing more research, its called rheology.
Its basically a study of things that change viscosity like these fluids, and also non newtonian fluids, like the shear-thickening fluid we talked about.
Im surprised we dont see more aplications of this stuff...it seems very useful...
Maybe ill have to make some cool usages of it!
 

Offline Mr Andrew

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Re: Liquid magnet
« Reply #21 on: 09/06/2006 02:21:56 »
While we're talking about magnets, I did some research and found out that people have used strong magnets to levitate objects like water and a frog! Every molecule in the frog is polarized to make it diamagnetic. Pretty neat stuff there too. Hover cars?!:)

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Offline ukmicky

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Re: Liquid magnet
« Reply #22 on: 09/06/2006 02:33:59 »
quote:
Originally posted by Mr Andrew

While we're talking about magnets, I did some research and found out that people have used strong magnets to levitate objects like water and a frog! Every molecule in the frog is polarized to make it diamagnetic. Pretty neat stuff there too. Hover cars?!:)

"His mind is the ultimate weapon!"-MacGyver television series

SO COULD THEY LEVITATE ME, WOULD THERE BE ANY HARMFUL EFFECTS

Michael
 

Offline Mr Andrew

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Re: Liquid magnet
« Reply #23 on: 09/06/2006 23:15:06 »
It is theoretically possible to levitate a human but you would need quite a magnetic field.  It's something to work towards.

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another_someone

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Re: Liquid magnet
« Reply #24 on: 10/06/2006 02:16:57 »
quote:
Originally posted by ukmicky
SO COULD THEY LEVITATE ME, WOULD THERE BE ANY HARMFUL EFFECTS



I would have thought that if this was achievable, that some parts of your body would be more susceptible to magnetic fields than other parts, so while some parts are being dragged up by the magnetic fields, other parts are being dragged down by gravity.  May be, at very least, a somewhat uncomfortable experience (the exact effect I would guess would depend upon which parts get dragged up and which are still trying to fall down under gravity).



George
 

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Re: Liquid magnet
« Reply #24 on: 10/06/2006 02:16:57 »

 

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