Ferrofluid – the magnetic liquid!

Materials scientist and Christmas Lecturer Mark Miodownik demonstrates some of the weird properties of ferrofluid. This liquid is literally ‘dripping with magnetism’, containing a suspension of ferromagnetic nanoparticles that make the liquid responsive to external magnetic fields, generating unusual patterns, shapes and motion.

Using a strong neodymium magnet and a large steel bolt, Mark demonstrates the strange and beautiful patterns the fluid forms in response to the magnetic field. Ferrofluids do not tend to maintain their behaviour in the absence of an external magnetic field and are therefore known as superparamagnets.