Method for producing a piezoelectric stack actuator, and piezoelectric stack actuator

A method for producing a piezoelectric stack actuator, the method comprising:

• a. Step A:
• providing at least two actuators, each actuator including a top and a bottom surface configured to be connected directly, or indirectly via an additional element, to a respective top or bottom surface of an adjacent actuator, the at least two actuators are configured and designed to generate a deflection along an axis (A) when electrically activated, wherein step A includes sub-steps of:
• Sub-step A1:
• providing piezoceramic layers and electric contacts to make up the at least two actuators as multi-layer actuators, and
• Sub-step A4:
• enveloping the piezoceramic layers and the electric contacts with a ceramic insulating material;
• and
• b. Step B:
• mechanically coupling the at least two actuators to define a mutual coupling area (K) including ceramic insulating material of the enveloped piezoceramic layers between each two adjacent actuators to form the stack actuator that is centered and stacked along a stacking axis (S) such that deflections of the actuators generated when the actuators are electrically activated will be overlaid along the stacking axis (S) and there is a force-coupling of the actuators over the coupling area (K), wherein the coupling area (K) is smaller than a projection area (P) resulting from a projection of each of the actuators onto a plane (E) perpendicular to the stacking axis (S).