A magnetic stirrer or magnetic mixer is a laboratory device that employs a rotating magnetic field to cause a stir bar (or flea) immersed in a liquid to spin very quickly, thus stirring it. The rotating field may be created either by a rotating magnet or a set of stationary electromagnets placed beneath the vessel with the liquid. It is used in chemistry and biology where other stirring forms, such as motorized stirrers and stirring rods, may not be viable for use.
