Design and technology as well as science teachers are buying the amazing Ferro fluid – a truly magnetic liquid. This consists of micron size magnetic particles (magnetite) in a mineral oil. Particles are coated in a surfactant which prevents them clumping together.
When a magnet is in close proximity the magnetic particles in the Ferro fluid take up the shape of the magnetic field – a 3-D version of the classic iron fillings on a piece of paper experiment that we used to do in schools.
The apparent density of Ferro fluid can be changed by applying a magnetic field. E.g. place a one pence piece in a shallow dish (5mm) of Ferro fluid and it will sink. Bring a powerful magnet underneath and the coin will float!
Supplied in a plastic jar containing 10ml of Ferro fluid. A rare earth magnet is also supplied.