Piezoelectric actuator, method for producing piezoelectric actuator, liquid transporting apparatus, and method for producing liquid transporting apparatus

A method for manufacturing a liquid transporting apparatus including a channel unit having a plurality of pressure chambers arranged along a plane, and a piezoelectric actuator which is provided on a surface of the channel unit and which selectively changes volumes of the plurality of pressure chambers, the method comprising:

• a piezoelectric layer forming step of forming a piezoelectric layer on a surface of a vibration plate which covers the pressure chambers and which has a first electrode provided on a surface of the vibration plate, the piezoelectric layer being polarized in a direction of thickness of the piezoelectric layer and formed on the surface of the vibration plate provided with the first electrode, the first electrode being provided at an area of the vibration plate which faces the pressure chambers, the area being on a side of the vibration plate opposite to the pressure chambers;
• a thickness measuring step of measuring thicknesses of the piezoelectric layer at areas each of which overlaps with one of the pressure chambers and the first electrode in a plane view;
• a step of forming a conductive layer entirely over a surface of the piezoelectric layer on a side opposite to the first electrode;
• and
• a step of forming second electrodes in areas, of the conductive layer, defined by a hole formed in the conductive layer by adjusting lengths in a predetermined direction of the second electrodes in positive correlation with the measured thicknesses of the piezoelectric layer at first portions each of which is interposed between the first electrode and one of the second electrodes, the first portions displacing to change the volumes of the pressure chambers;
• wherein the piezoelectric layer is formed to have second portions each of which is not interposed between the first electrode and one of the second electrodes, and which do not displace to change the volumes of the pressure chambers.