A piston actuator comprising: a housing defining a chamber and comprising a port in fluid communication with the chamber; a piston at least partially comprising a ferromagnetic material, a magnet or both thereof, and having a sealing member about an outer periphery thereof, the piston disposed within the housing with the sealing member positioned as a lip seal against an interior surface of the chamber; a spring seated against the piston to bias the piston into a starting position; and a secondary magnet or ferromagnetic material forming a first magnetic/ferromagnetic pair with the piston and positioned to maintain the piston in a secondary position once the piston moves to the secondary position; a tertiary magnet or ferromagnetic material forming a second magnetic/ferromagnetic pair with the piston and positioned to assist the spring in maintaining the piston in the starting position; wherein, when the introduction of fluid into or the removal of fluid from the chamber via the port overcomes the force of the spring and the attraction between the members of the second magnetic/ferromagnetic pair holding the piston in the starting position, the attraction between the members of the first magnetic/ferromagnetic pair moves the piston to the secondary position as a snap movement and thereafter maintains the piston in the secondary position, and when the attraction between the members of the first magnetic/ferromagnetic pair is overcome by the force of the spring and the introduction or removal of fluid form the chamber, the attraction between the members of the second magnetic/ferromagnetic pair in addition to the spring force moves the piston to the starting position as a snap movement and thereafter maintains the piston in the starting position; wherein either or both of the secondary magnet or ferromagnetic material and the tertiary magnet or ferromagnetic material are part of the housing as an annular magnet or annular ferromagnetic material defining a first surface that is flush with a first interior surface of the housing, and the first surface has physical contact with an upper surface of the piston in the secondary position to create a seal for a vacuum connected to the chamber via the port. a housing defining a chamber and comprising a port in fluid communication with the chamber; a piston at least partially comprising a ferromagnetic material, a magnet or both thereof, and having a sealing member about an outer periphery thereof, the piston disposed within the housing with the sealing member positioned as a lip seal against an interior surface of the chamber; a spring seated against the piston to bias the piston into a starting position; and a secondary magnet or ferromagnetic material forming a first magnetic/ferromagnetic pair with the piston and positioned to maintain the piston in a secondary position once the piston moves to the secondary position; a tertiary magnet or ferromagnetic material forming a second magnetic/ferromagnetic pair with the piston and positioned to assist the spring in maintaining the piston in the starting position; wherein, when the introduction of fluid into or the removal of fluid from the chamber via the port overcomes the force of the spring and the attraction between the members of the second magnetic/ferromagnetic pair holding the piston in the starting position, the attraction between the members of the first magnetic/ferromagnetic pair moves the piston to the secondary position as a snap movement and thereafter maintains the piston in the secondary position, and when the attraction between the members of the first magnetic/ferromagnetic pair is overcome by the force of the spring and the introduction or removal of fluid form the chamber, the attraction between the members of the second magnetic/ferromagnetic pair in addition to the spring force moves the piston to the starting position as a snap movement and thereafter maintains the piston in the starting position; wherein either or both of the secondary magnet or ferromagnetic material and the tertiary magnet or ferromagnetic material are part of the housing as an annular magnet or annular ferromagnetic material defining a first surface that is flush with a first interior surface of the housing, and the first surface has physical contact with an upper surface of the piston in the secondary position to create a seal for a vacuum connected to the chamber via the port.