How ferrofluids work

Ferrofluids are made up of tiny magnetic fragments of iron suspended in kerosene or oil with a surfactant to prevent them from clumping. Although expensive to buy online, you can make ferrofluid easily and cheaply at home.

From speakers to computer hard drives, there are many ways ferrofluids are used commercially. The oily fluid prevents debris from entering hard drives when a small amount is placed between the magnets and shaft. In the case of speakers ferrofluids remove heat from the voice coils and help dampen the cone movement. Ferrofluids can be used to help make dynamic molds by pouring a hardening agent over the fluids.

Interested in learning how to make your own ferrofluids at home? Check out this great DIY article from Popular Mechanics

Here’s a great video by Michael Flynn explaining how ferrofluids work in more detail.