Patent ID: 7309944

Claim:
Piezoactuator ( 1 ) comprising at least one stacked piezoelement ( 2 ), with at least two electrode layers ( 7 , 8 , 9 ), arranged one over the other along a stacking direction ( 10 ) of the piezoelement ( 2 ), and at least one piezoelectric layer ( 4 ), arranged between two electrode layers ( 7 , 8 , 9 ), and at least one pretensioning device ( 15 ) for introduction of force ( 32 ) into a volume of the piezoelectric layer ( 4 ) by means of at least one force introduction surface ( 13 , 14 , 23 , 24 ) on the piezoelectric layer ( 4 ), which is arranged on at least one of the surface sections ( 11 , 12 ) of the piezoelectric layer ( 4 ) so that it faces the pretensioning device ( 15 ), wherein the force introduction surface ( 13 , 14 , 23 , 24 ) is smaller than the surface section ( 11 , 12 ) of the piezoelectric layer ( 4 ) and that the volume is a partial volume ( 5 ) of the piezoelectric layer ( 4 ); wherein a thickness ( 6 ) selected for the piezoelectric layer ( 4 ) is in the range 20 μm to 200 μm inclusive; and wherein an extent of the force introduction surface ( 13 , 14 , 23 , 24 ) virtually corresponds to the thickness ( 6 ) of the piezoelectric layer ( 4 ).