Patent ID: 7044586

Claim:
A piezoelectric/electrostrictive film type actuator comprising: a ceramic substrate comprising a plurality of laminated thin plate layers and having a cavity formed in an internal portion thereof; and a piezoelectric/electrostrictive device disposed on one surface of said ceramic substrate and including a plurality of piezoelectric/electrostrictive films and electrode films; wherein said piezoelectric/electrostrictive films and said electrode films are alternately laminated such that electrode films form uppermost and lowermost layers of said piezoelectric/electrostrictive device; wherein said actuator is driven by displacement of said piezoelectric/electrostrictive device such that said uppermost electrode film moves and said cavity is pressurized by deforming a part of a wall thereof with said piezoelectric/electrostrictive device; wherein a thickness of said piezoelectric/electrostrictive device, when viewed in cross-section, decreases from a central portion thereof toward opposite outer portions thereof; and wherein an upper surface of said piezoelectric/electrostrictive device, when viewed in cross-section, has a convex arcuate shape, and a radius of curvature of said convex arcuate shape originates from a point located below said one surface of ceramic substrate.