What are ferromagnetic liquids used for?
Ferrofluid is used in rotary seals in computer hard drives and other rotating shaft motors. Loudspeakers use ferrofluid to dampen vibrations. In medicine, ferrofluid is used as a contrast agent for magnetic resonance imaging (MRI).
What is ferromagnetic fluid?
Ferrofluids are paramagnets that consist of magnetic nanoparticles dispersed in a liquid. When exposed to a magnetic field, the combined effects of gravity, surface tension and the magnetic attraction between nanoparticles can create unusual spiky structures on the surfaces of ferrofluids.
What do you mix ferrofluid with?
Pour a bit of vegetable oil into a shallow dish, just enough to make a thin film across the bottom. Pour iron filings into the oil and mix the two until they have become a thick, sludge-like material. This is your ferrofluid! Use a napkin to absorb any excess oil and allow the ferrofluid to become thicker.
Why would ferrofluid not spike?
If too much water is added, the ferrofluid will become too dilute and will not spike. If the ferrofluid is too dilute, hold the strong magnet under the weighing boat, then tilt the weighing boat so that the excess liquid runs off.
How is ferrofluid used in speakers?
In speakers, Ferrofluid is used to liquid cool voice coils, damp resonances and help center the voice coils. All can improve the sound quality and quantity. Ferrofluid can prevent burning out voice coils in speakers. Ferrofluid is a liquid that has very small particles of a magnetic material suspended in it.
What are iron filings used for?
Iron filings are tiny rods of iron. They are often used to show the effects of magnetic fields. Since iron is magnetic, the filings become small bar magnets. Each filing attracts other filings, so the filings eventually look like the magnetic field the original magnet has.
Is ferro fluid safe?
The toxicity of ferrofluid is very low; animal experiments in which the permissible maximum doses of ferrofluid were either administered orally, intravenously, or intraperitoneally did not kill the mice.
What happens if you touch ferrofluid?
+ What would happen if I touched ferrofluid with my finger? You would get a dirty finger, and its very difficult to get off. Wash your hands with soap and water.
What liquid is in ferrofluid?
Ferrofluids are made up of tiny magnetic fragments of iron suspended in oil (often kerosene) with a surfactant to prevent clumping (usually oleic acid). The fluid is relatively easy to make at home yet extremely expensive to buy on-line.
Why is a surfactant used in making your ferrofluid?
These surfactants prevent the nanoparticles from clumping together, so the particles can not fall out of suspension nor clump into a pile of magnetic dust on near the magnet. The magnetic particles in an ideal ferrofluid never settle out, even when exposed to a strong magnetic field.
Why do ferrofluids form spikes?
A ferrofluid forms spikes along the magnetic field lines when the magnetic surface force exceeds the stabilizing effects of fluid weight and surface tension (see photo). The ferrofluid has low resistance to flow, so it can function as a liquid O-ring seal, kept in place with permanent magnets.
What does ferrofluid do in tweeters?
Many speakers produced from 1990 until today have (metal)dome tweeters damped with “ferrofluid.” The concept is that the viscous fluid containing microscopic metal parts, magnetically held in the tweeter voice coil gap, damps resonances as well as cools the voice coil – thus improving sound quality and prevent …
Is it easy to make your own ferromagnetic fluid?
Making your own ferromagnetic fluid (ferrofluid) is super easy, and it uses the same easy to get black iron oxide powder as the magnetic putty. The best thing about ferromagnetic fluid is that there’s many ways to make it.
Why are ferromagnetic particles used in magnetic fluids?
Ferromagnetic particles are used because of their large magnetic permeability, as compared to other classifications of magnets. Essentially, the resultant magnetic field is orders of magnitude larger than the induced magnetic field, which becomes important when manipulating ferrofluids under moderate and controlled magnetic fields.
What can ferrofluid be used for in a computer?
It can also be used as a liquid seal in many electronic devices. For example, in computer hard-drives ferrofluid can be used to form a seal around the rotating shaft.
Which is the most beautiful application of ferromagnets?
One of the most beautiful applications of ferromagnets is ferrofluids. These are suspensions of sub-micrometre-sized magnetic particles in organic solvents, such as kerosene, with a surfactant soap to keep them dispersed 3.