Patent ID: 7589450

Claim:
An actuator device comprising: a layer provided on a single crystal silicon (Si) substrate, and made of silicon dioxide (SiO 2 ); at least one buffer layer provided on the layer made of silicon dioxide (SiO 2 ); a base layer provided on the buffer layer, and made of lanthanum nickel oxide (LNO) having the ( 100 ) plane orientation; and a piezoelectric element comprising: a lower electrode provided on the base layer, and made of platinum (Pt) having the ( 100 ) plane orientation; a piezoelectric layer made of a ferroelectric layer whose plane orientation is the ( 100 ) orientation, the piezoelectric layer formed on the lower electrode by epitaxial growth where a crystal system of at least one kind selected from a group consisting of a tetragonal system, a monoclinic system and a rhombohedral system dominates the other crystal systems; and an upper electrode provided on the piezoelectric layer.