An electrostatic actuator having a base (10) including a first electrode (20), and having a flexible membrane (50) including at least two material layers of different materials in contact with each other. At least one of the material layers includes a second electrode (40) electrically isolated from the first electrode. The flexible membrane includes a fixed end where the flexible membrane connects to the base and a free end opposite the fixed end. In the flexible membrane, the second electrode has at least first and second portions separated by a third portion an in combination defining a step provided in a vicinity of the fixed end. The first step is closest to the fixed end and separated by a shorter distance from the first electrode than the second portion. A stiffening member (310) can be disposed on the flexible membrane toward the free end of the flexible membrane. The electrostatic actuator can include an elongated orifice (420,320) extending through the base and extending along a direction away from the fixed end. The first electrode of the base can extends past an end of the second electrode of the flexible membrane in a direction defined toward the fixed end. The flexible membrane can include a peripheral or side cut out configured to communicate to an interior of the flexible membrane.