Fluidic Magnets

Fluidic magnets, typically constructed using ferrofluid, are found in many household and electrical products. Understanding what a liquid magnet is and how it works is the first step to understanding why it is used in many products. Liquid magnets are constructed of a colloidal substance on the Nano scale, which has been suspended in a protective fluidic carrier; typically used is water or other organic solvents. A colloidal substance, in this case, liquid iron, is one that is suspended on a microscopic scale within its protective liquid evenly. This fluidic iron uses a surfactant to stop it from binding with other like particles.

What Ferrofluid Contains and its Many Uses?


In other words, ferrofluid is simply surfactant coated liquid iron suspended in a fluid. In many countries, art makers use it in their creations and it is used in decorative and functional magnets as well. Most ferrofluids contain 5% solid matter, 10% nonbinding agents, and 85% carrier fluids, using a volume measure. Fluidic magnets retain a shape only if a magnet force is present. If there is no magnetic field present, then it takes the shape of the container holding the liquid, the same way water does.





Some of the products that use ferrofluid include many electronics such as computer hard disk drive seals and audio speakers; in air craft to absorb some radar waves; in altitude control systems of NASA shuttles and, most notably, in magnetic resonance systems otherwise known as MRI scanners in the medical field. The medical field is also experimenting with the fluidic magnet for use in some cancer treatments, such as magnetic hyperthermia. In each instance the ferrofluid is used, a magnet changes the force of the fluid so it performs a different task.

Making Ferrofluids

Making ferrofluid is a simple task and one that anyone can complete at home. The materials needed include a jar or beaker to hold the contents, magnetic ink and a light lubricating oil or vegetable oil.  The best magnetic ink to use is the powdered type used in character recognition printing. Simply pour about a cup of oil into the container and add the magnetic ink to it in little amounts. After each addition of powdered ink, stir the mixture until it is completely wet. Remember that because it is a suspension, the ink will not dissolve in the oil, it will simply become wet. Continue adding magnetic ink until an oozing liquid is achieved. If the mixture is too thin, the magnetic field will not work properly. After experimenting with the consistency, take a hard magnet and hover it over the ferrofluid mixture in the container. If the correct consistency is achieved, the ferrofluid should raise into jagged peaks or other shapes.