Can a Liquid be Magnet?
However ferrofluids are referred to as a liquid magnet. Ferrofluids are colloidal mixtures of magnetic particles (~10 nm in diameter) in a liquid carrier. A typical ferrofluid is about 5% magnetic solids, 10% surfactant, and 85% carrier, by volume. In Electronics, Ferrofluids are used to form liquid seals around the spinning drive shafts in hard disks. The friction-reducing capabilities of Ferrofluids makes them usable in Mechanical Engineering.
There is another substance. Magnetorheological fluid or MR Fluid. When subjected to a magnetic field, the viscosity of the fluid increases to the extent of becoming a viscoelastic solid. Thus the ability to transmit force can be controlled with an electromagnet, which gives rise to its many possible control-based applications.