Abstract: The present disclosure relates to an electromechanical actuator, having a stack arrangement made of ceramic basis material having electromechanical properties and electrodes as well as a ceramic insulation for operation/use of the actuator in a humid environment. To ensure a long service life of the actuator with increased electromechanical expansion, an exemplary structure of the ceramic insulation has a smaller average grain size than the structure of the ceramic basis material. A method for the production of an actuator having ceramic insulation and a method for controlling such an actuator are also disclosed.

Abstract: A method for producing a piezoelectric stack actuator and a piezoelectric stack actuator are disclosed. To increase service life of a piezoelectric stack actuator made up of individual actuators, includes providing at least two actuators the method and designed and configured to generate a deflection along an axis (A) when electrically activated; and coupling the at least two actuators to form the stack actuator such that deflections of the actuators generated when the actuators are electrically activated are overlaid along a stacking axis (S) and there is a force-coupling of the actuators over at least one coupling area (K) that is smaller than a projection area (P) of the actuator onto a plane (E) perpendicular to the stacking axis.

Abstract: The disclosure relates to a piezoelectric drive, such as for permanently protected use in a moist environment, which includes a housing having a chamber, which chamber is hermetically sealed by at least one elastic membrane, and includes a piezoelectric drive unit in the hermetically sealed chamber for driving a drive element. The piezoelectric drive unit can include at least one piezoelectric bending actuator, which produces a bending deflection transversely to the elastic membrane when electrically activated. For example, two bending actuators can be arranged in series or parallel.