Ferrofluid is a substance that consists of tiny magnetic fragments of iron suspended in oil and a surfactant to prevent any clumping. Given that ferrofluids have magnetic particles, it’s only logical to assume that when they are exposed to magnetic field, the particles align with the field lines, which in return, makes the fluid much more dense.
There are many commercial applications for ferrofluid and hard drives and speakers are the most common. When a small amount of this oily fluid is placed between the shaft and the magnets it prevents debris from entering the hard drivers. In the case of the speakers, ferrofluid helps dampen the come movements by removing heat from the voice coils.
The fluid is easy to make at home and expensive to by online. Does $165 a liter sound good? Thus, in the video below, we’re checking out a cheap way to create ferrofluid using only a toner, magnet and oil. Check it out!