An actuator system is provided which includes a force transfer element and a force receiving element. A viscous material interconnects the force transfer element and the force receiving element. A workpiece, such as a valve member, is connected to the force receiving element. When a controlled force is applied to the force transfer element, the controlled force and resulting movement are rigidly coupled using the viscous material to the force receiving element so that the workpiece can be moved or otherwise operably controlled. When an uncontrolled force is received by the force transfer element, in which the movement of the force transfer element is slow relative to the deformation of the viscous material, there is no coupling of the uncontrolled force and resulting movement to the workpiece. As a result, the actuator system is able to couple rapid movements using the viscous material, while relatively slow movements are not coupled. Uncontrolled forces contemplated by this invention include forces resulting from stress, aging drift, and temperature variations associated with the force transfer element and the force receiving element.