Actuator with restoring springs

Actuator which can be moved from an initial position into a working position having at least one actuator element whose dimensions can be changed by an electrical signal, wherein at least two restoring means acting on the actuator element are provided for movement into the working position, the at least one actuator element being floatingly mounted between the at least two restoring means acting on said actuator element, characterized in that one of the at least two restoring means is a spring with a non-linear characteristic that is movable by a force from a first equilibrium position to a second equilibrium position different from the first one or in that a first restoring means comprises a body formed of a magnetic material which is arranged at a variable distance from a plate formed of a metal or a further body formed of a magnetic material, wherein the magnetic body and the plate or the further magnetic body have opposite or equal polarity on surfaces facing each other.