A ferrofluid (from the Latin ferrum, meaning iron) is a liquid which becomes strongly polarised in the presence of a magnetic field.
Ferrofluids are tiny iron particles covered with a liquid coating, also surfactant that are then added to water or oil, which gives them their liquid properties. Ferrofluids are colloidal suspensions -- materials with properties of more than one state of matter. In this case, the two states of matter are the solid metal and liquid it is in. This ability to change phases with the application of a magnetic field allows them to be used as seals, lubricants, and may open up further applications in future nanoelectromechanical systems.
Artists Sachiko Kodama and Yasushi Miyajima create magnificently surreal kinetic sculptures where a liquid filled with nanoscale ferromagnetic particles flows, rotates, and shapeshifts around a simple iron tower structure in response to shifts in a magnetic field. The piece is titled "Morpho Towers — Two Standing Spirals" (2006-2007).
This technique uses one electromagnet, and its iron core is extended and sculpted. The ferrofluid covers the sculpted surface of a three-dimensional iron shape that was made on an electronic NC lathe. The movement of the spikes in the fluid is controlled dynamically on the surface by adjusting the power of the electromagnet. The shape of the iron body is designed as helical so that the fluid can move to the top of the helical tower when the magnetic field is strong enough.
The surface of the tower responds dynamically to its magnetic environment. When there is no magnetic field, the tower appears to be a simple spiral shape. But when the magnetic field around the tower is strengthened, spikes of ferrofluid are born; at the same time, the tower’s surface dynamically morphs into a variety of textures ranging from soft fluid to minute moss, or to spiky shark’s teeth, or again to a hard iron surface. The ferrofluid, with its smooth, black surface that seems to draw people in, reaches the top of the tower, spreading like a fractal, defying gravity.