Head chips and related devices for inkjet printers

A head chip comprising:

• a flow channel member provided with a pressure chamber containing a liquid;
• an actuator plate which is arranged on the flow channel member in a state of being opposed in a first direction to the pressure chamber, and which has a polarization direction set to the first direction;
• and
• a drive electrode which is formed on the actuator plate, and which is configured to deform the actuator plate in the first direction to change a volume of the pressure chamber, wherein
• a shape changing part is formed in a portion of the actuator plate, the shape changing part comprises a protruding part protruding with respect to a first surface facing to the flow channel member in the first direction or a recessed part recessed with respect to the first surface, and the shape changing part overlaps the pressure chamber when viewed from the first direction, and
• the drive electrode includes
• a first electrode formed on a surface of the shape changing part, and
• a first opposed electrode which is formed on a second surface of the actuator plate so as to be opposed to the first electrode, the second surface facing to an opposite side to the first surface in the first direction, and which is configured to generate a potential difference from the first electrode.