Electrostatic actuator and manufacturing method therefor

摘要

An electrostatic actuator comprising opposing electrode members displaced relatively by an electrostatic force is provided with improved durability so that electrostatic attraction between opposing members does not drop and the opposing electrode members do not stick together. Hydrophobic films of hexamethyldisilazane (HMDS) are formed on a surface of segment electrode and a bottom surface of a diaphragm (common electrode) of an eletrostatic actuator wherein the diaphragm forms a wall of an ink chamber in an ink jet head. HMDS molecules are smaller than PFDA molecules, and a uniform, variation-free hydrophobic film can therefore be formed even when the gap between opposing electrodes is narrow. Durability and film stability of a HMDS hydrophobic film are also high. An electrostatic actuator with high durability and operating stability can thus be achieved.