Magnetic Fluids

The scientists at NASA are busy people. Since the late 1950s, NASA scientists have invented many things to help people explore space. Some of these inventions have led to products that make life a little easier for people on Earth, too!

NASA scientists have helped create barcodes, TV satellite dishes, ear thermometers, ski boots, and smoke detectors. These are just a few of the everyday products that people use thanks to NASA.

About thirty years ago, NASA scientists were studying the problem of moving rocket fuel. When a rocket leaves the atmosphere, it is no longer affected by gravity. The scientists wanted to invent a way to help move rocket fuel from the fuel tank through fuel pipes to the engine. Without the force of gravity, it was a tricky task. The scientists decided to put lots of little pieces of iron inside of the rocket fuel. Then they used a magnet to help pull the fuel through the fuel pipe. What they created was a magnetic fluid.

A magnetic fluid is a liquid with a magnetic substance, such as iron, suspended in the fluid. When a magnet is moved near the magnetic fluid, all of those little pieces of iron line up and create a rigid web inside of the fluid. This web allows the motion of the fluid to be controlled by a magnet.

Since experimenting with rocket fuel thirty years ago, scientists have looked at other uses for magnetic fluids. Today, magnetic fluids are used in shock absorbers for some cars. Magnetic fluids have also been built into the structure of a few buildings. These buildings are in areas on the Earth's surface that have a lot of earthquakes. The magnetic fluid in a building's structure acts like a shock absorber when an earthquake hits. Scientists are also studying ways to use magnetic fluids to make robots with more human-like movement.

Who knows what magnetic fluids will help people do in the future?

Vocabulary

fluid:
A substance, such as air or water, that flows easily and takes the shape of its container. All liquids and gases are fluids.
liquid:
A state of matter that does not have its own shape.
NASA:
The National Aeronautics and Space Administration.
shock absorber:
A device used to lessen an impact.
suspend:
To hang.

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Activity

  1. What is a magnetic fluid?
    Answer: A magnetic fluid is a liquid with a magnetic substance suspended in the fluid.
  2. Do you think a magnet attracts or repels the substance in a magnetic fluid? Why?
    Answer: Answers may vary but could include that a magnet attracts the substance in a magnetic fluid. This attraction is what allows the fluid's direction to be controlled. Students may answer that the magnetic substance is repelled by a magnet and that this repulsion could also be used to control the fluid.
  3. Draw a picture that shows what a magnetic fluid might look like when there is no magnet near it. Then draw another picture that shows what that magnetic fluid might look like when a magnet is placed near the fluid. Show pieces of the magnetic substance in both pictures. Your picture should show how the organization of the magnetic substance differs when there is no magnet and when there is a magnet.
    Answer: Drawings may vary but should include a picture that represents the presence of no magnet and should show particles floating in random order inside of a fluid. The second picture should show the presence of a magnet and the particles in some sort of patterned order, such as particles lined up in a grid or in rows.

Activity

  1. What is a magnetic fluid?
    Answer: A magnetic fluid is a liquid with a magnetic substance suspended in the fluid.
  2. Do you think a magnet attracts or repels the substance in a magnetic fluid? Why?
    Answer: Answers may vary but could include that a magnet attracts the substance in a magnetic fluid. This attraction is what allows the fluid's direction to be controlled. Students may answer that the magnetic substance is repelled by a magnet and that this repulsion could also be used to control the fluid.
  3. Draw a picture that shows what a magnetic fluid might look like when there is no magnet near it. Then draw another picture that shows what that magnetic fluid might look like when a magnet is placed near the fluid. Show pieces of the magnetic substance in both pictures. Your picture should show how the organization of the magnetic substance differs when there is no magnet and when there is a magnet.
    Answer: Drawings may vary but should include a picture that represents the presence of no magnet and should show particles floating in random order inside of a fluid. The second picture should show the presence of a magnet and the particles in some sort of patterned order, such as particles lined up in a grid or in rows.