US Patent 7126254 Actuator element and device including the actuator element

An actuator element has a plate member, a piezoelectric/electrostrictive body disposed in facing relation to the plate member, and a beam disposed between the plate member and the piezoelectric/electrostrictive body and fixing the piezoelectric/electrostrictive body to the plate member. The piezoelectric/electrostrictive body has a piezoelectric/electrostrictive layer, an upper electrode formed on a surface of the piezoelectric/electrostrictive layer which faces the plate member, and a lower electrode formed on a surface of the piezoelectric/electrostrictive layer which is opposite to the surface thereof facing the plate member. When an electric field is applied to the upper electrode and the lower electrode, a portion of the piezoelectric/electrostrictive body is displaced toward or away from the plate member.