A thermo-magnetic
actuator includes a housing; a chamber within the housing; a
working fluid changing phase upon heating and located in the chamber; an electrical heater disposed within the chamber for heating the
working fluid upon application of electrical power to the electrical heater; a
piston rod slidably disposed in the housing and movable between a retracted position, retracted with respect to the housing, and an extended position extending substantially outward of the housing, the
piston rod being driven and sliding from the retracted position to the extended position in response to heating of the
working fluid by the electrical heater; a spring biasing the
piston rod toward the retracted position; an
electromagnet disposed at an end of the housing and generating a
magnetic field when an
electric current is supplied to the
electromagnet; and a ferromagnetic target
assembly attached to the
piston rod, sliding within the housing, and attracted toward the
electromagnet, when an
electrical current flows through the electromagnet, to maintain the
piston rod in the extended position even if electrical power is no longer applied to the heater. Preferably, the position of the
piston rod is detected by the
actuator and
electrical current flow to the electrical heater is terminated when the piston rod is detected at the extended position.