Ferrofluid is a really interesting material. As the name suggests it is a runny fluid....until it is subjected to a magnet. Ferrofluid reacts to magnetic fields, often changing into seemingly impossible shapes as it tries to maintain the shape of the magnetic field. The most common form of ferrofluid is ultra fine iron particles which have been nano-coated and then suspended in another liquid. To the naked eye it just seems like a very dark brown/black liquid that responds to magnetism.
Ferrofluid has been extensively used as a bearing/shaft seal, as it can maintain a
relatively low friction, create a very good seal, allow high spin speeds and a simple
magnetic can keep it exactly where it is needed. Ferrofluid is now commonly found as a
seal on high-end hard disks.It has also found its way into exotic cars into the form of
magnetorheological fluid (MagneRide ) in the suspension dampeners. An electrical current is passed through the dampener whenever a restriction of the dampener movement is required. This can be controlled tens of times a second as the car is driving over different road surfaces.
Variations of ferrofluid has also been rumoured to be used stealth aircraft technology in the form of Rader Absorbent Material (RAM).
Ferrofluid is supplied in a container of 50ml.