Piezoelectric/electrostrictive element

A method of driving a piezoelectric/electrostrictive element, comprising the steps of:

• providing a piezoelectric/electrostrictive element comprising (i) a fixed section having a window formed therethrough, (ii) a vibrating section closing the window of the fixed section and supported by the fixed section in a vibrative manner, and (iii) a uni-morph type piezoelectric/electrostrictive operating section including a piezoelectric/electrostrictive layer having a first principal surface on which first and second laterally spaced electrodes are formed and an opposed second principal surface in operative contact with the vibrating section, wherein a region of the piezoelectric/electrostrictive layer between the first and second electrodes has a uniform polarization direction throughout substantially the entire thickness of the piezoelectric/electrostrictive layer;
• applying a first electric field between the first and second electrodes in a direction coincident with the polarization direction in said region of the piezoelectric/electrostrictive layer;
• and
• applying a second electric field between the first and second electrodes in a direction opposite to the polarization direction in said region of the piezoelectric/electrostrictive layer, said second electric field being of sufficient magnitude to reverse the polarization direction in an upper portion of said region of the piezoelectric/electrostrictive layer;
• whereby displacement of the piezoelectric/electrostrictive element is different even when the absolute magnitudes of the first and second electric fields are equal.