Piezoelektrischer Aktor mit veraenderbarer Steifigkeit

A piezoelectric actuator of variable rigidity consists of one or more adjacent or overlying individual elements, each comprising a multilayer contractor (3) with alternate side parallel-connected inner electrodes (4). Top and bottom Al2O3 plates (1) are bonded to the contractor, at least at its outer edges, and are coated, at the side facing the contractor, with a PZT thick film (2) provided with electrodes. ADVANTAGE - The actuator exhibits an extension of about 1% of its thickness at 200 V, allows large area deflection and, compared with similar prior art Moonie elements, allows application of much larger adjustment forces.