Piezoelectric actuator, method of manufacture, and ink-jet print head

A method of manufacturing a piezoelectric actuator, formed of multiple concave parts which are provided on one surface. First, a first sheet is formed of pliant piezoelectric materials and a second sheet is formed of pliant predetermined materials, forming an upper electrode layer formed of conduction materials on one surface of said first sheet, and forming a lower electrode layer formed of conduction materials on the other surface of said first sheet or one surface of said second sheet, wherein piezoelectric material is used as said material of the second sheet and electrode layer for polarization formed of conduction material is formed on the other surface side of said second sheet. Next, the first and second sheets are piled and densified. The first sheet is polarized in a direction of a thickness of the first sheet. In a fourth step, the upper electrode layer is patterned in order to form multiple electrodes corresponding respectively to each pressure chamber of the pressure chamber forming unit, wherein by placing a voltage between the upper electrode layer and the electrode layer for polarization, the first sheet is polarized in the direction of its thickness.