Electrostatic actuator, liquid droplet discharging head, methods for manufacturing them, and liquid droplet discharging apparatus

Abstract

To allow formation of an insulation film to be applied even to a glass substrate without depending on a substrate material so as to improve pressure generated by an electrostatic actuator, as well as to achieve improvement in driving stability and driving durability of the electrostatic actuator at a low cost. An electrostatic actuator including an individual electrode formed on a substrate, a vibration plate arranged opposite to the individual electrode via a predetermined gap and a driving means for causing a displacement of the vibration plate by generating an electrostatic force between the individual electrode and the vibration plate includes an insulation film provided on one or both of opposing surfaces of the fixed electrode and the movable electrode and a surface protection film provided on the insulation film. The surface protection film is made of a hard ceramic film or a hard carbon film.