A ferrofluid is a liquid which becomes strongly polarized in the presence of a magnetic field. It is a colloidal mixture comprising extremely small magnetic particles suspended in a liquid. Ferrofluids are composed of nanoscale ferromagnetic, or ferrimagnetic, particles suspended in a carrier fluid, usually an organic solvent or water. The ferromagnetic nano-particles are coated with a surfactant to prevent their agglomeration. Research of colloidal suspensions of fine magnetic particles at Carnegie Mellon University has found applications in biomed sectors.
