Abstract: Magnetic stir bar having at least one permanent magnet to spin the magnetic stir bar when the magnetic stir bar is subjected to a rotating magnetic field. The magnetic stir bar has a chamber to store a product within the magnetic stir bar. The magnetic stir bar has a closed configuration in which the chamber is closed and an open configuration in which the chamber is open. The magnetic stir bar automatically reconfigures itself from the closed configuration to the open configuration when said magnetic stir bar is spun at or above a threshold rotational speed.

Abstract: Magnetic stir bar (1) for use with a magnetic stirrer, said magnetic stir bar (1) comprising at least one permanent magnet (2) for spinning said magnetic stir bar (1) when said magnetic stir bar (1) is subjected to a rotating magnetic field; and a chamber (3) for storing a product inside said magnetic stir bar (1), wherein said magnetic stir bar (1) has a closed configuration in which said chamber (3) is closed, said magnetic stir bar (1) being maintained in said closed configuration under the effect of a first force (f), and an open configuration in which said chamber (3) is open, said magnetic stir bar (1) being maintained in said open configuration under the effect of a second force (F); and wherein said magnetic stir bar (1) is adapted to automatically reconfigure itself from said closed configuration to said open configuration when said magnetic stir bar (1) is spun at or above a threshold rotational speed (?t).