Invented in the 1960s, ferrofluid was initially used to help form seals in equipment where ordinary seals couldn't be used. However, recent advancements in modeling of ferrofluids have revealed other potential applications, ranging from automobile shocks to drug delivery.
Amazing But True
- Ferrofluids are liquids with extremely small ferromagnetic particles. The iron particles range in size from 5 to 10 nanometers in diameter. Each ferromagnetic particle is coated with a liquid that prevents clumping, which lowers surface tension.
- When a magnetic field is applied to a ferrofluid, spikes can be seen that lie the direction of the magnetic field lines. The spikes that are seen are a result of the magnetic spheres inside the fluid lining up and making chains parallel to the magnetic field lines.
- In aerospace, ferrofluids are used to reduce friction when magnets are required to slide across specific surfaces. In regards to automobiles, the shocks in some high end luxury cars use ferrofluids in their shock absorbers to allow for a more pleasurable ride. The uses for ferrofluids touch into many different industries, and new applications are constantly being discovered.
- Watch a video of ferrofluid sculptures: http://www.youtube.com/watch?v=XUz1ZI-w6LQ
Using the information provided above, answer the following questions.
- If you didn't have a magnet, what else could you use to 'activate' a ferrofluid?
- The size of the particles in a ferrofluid are very important. Why do you suppose this is?
- If you were to cover a spherical magnet in a ferrofluid, what direction would the spikes point?