Actuator, positioning system and lithographic apparatus

摘要

Actuator for exerting a force and a torque on an object, wherein the actuator includes a first part that is movable with respect to a second part of the actuator in at least a first degree of freedom, wherein the object is mounted to the first part, wherein one of the parts is provided with a first electrical coil that is arranged to cooperate with a magnetizable portion of the other part and wherein a controller of the actuator is arranged to generate a first electrical current through the first electrical coil for generating a force between the parts, wherein the one of the parts is provided with a second electrical coil which is arranged to cooperated with a magnetizable portion of the other part, wherein the controller is further arranged to generate a second current through the second coil and the first current through the first electrical coil for exerting the force and torque between the parts so that the actuator is arranged to exert the force and the torque on the object with respect to the second part.