Electrostatic actuator and method of manufacturing it

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 the opposing electrode members does not drop and the opposing electrode members do not stick together. Hydrophobic films (22) and (23) of hexamethyldisilazane (HMDS) are formed on the surface of a segment electrode (19) and the bottom surface of a diaphragm (common electrode) (6) of electrostatic actuator wherein the diaphragm forms a wall of an ink chamber 7 in a ink jet head 1. HMDS molecules are smaller than PFDA molecules, and a uniform, variation-free hydrophobic film can therefore be formed even when the gap between the two electrodes is narrow. Durability and film stability of hydrophobic films are also high. An electrostatic actuator with high durability and operating stability can thus be achieved. <IMAGE>