Scientists Say: Ferrofluid

This is a fluid that responds to magnetic fields

This isn’t a flower — it’s a ferrofluid! These liquids, which contain tiny iron particles, naturally form peaks and valleys when a magnet is placed below them.

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Ferrofluid (noun, “FAIR-oh-flu-id”)

This is a fluid with tiny magnetic particles floating in it. The fluid can be water, oil or something else. The particles need to contain iron or another element — such as cobalt or nickel — that act like a magnet. In fact, “ferro-“ is Latin for iron (which has the chemical symbol “Fe”). The engineer Steve Papell invented the first ferrofluid in the 1960s.

When a ferrofluid is placed near a magnet, the magnet attracts the iron-containing particles. This causes the whole liquid to become magnetic. And this makes ferrofluids useful in many industries. Ferrofluids are used as liquid seals to keep dust out of computer hardrives. They can also be used in loudspeakers to help keep them cool. Researchers are even exploring whether ferrofluids can carry medicines to hard-to-reach places inside the body.

In a sentence

Scientists hope they could one day use a ferrofluid to help clean up oil spills.

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Bethany Brookshire is the staff writer at Science News for Students. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.