Patent ID: 8389084

Claim:
An actuator based device, comprising: a body containing a chamber to receive a fluid; a piezoelectric actuator adjacent to the chamber, the piezoelectric actuator being in the form of a layer and comprising a first surface facing the chamber, a second surface opposite to the first surface, the second surface being away from the chamber, the second surface comprising a center region, at least one edge surface between the first surface and the second surface, and at least one corner connecting the second surface and the at least one edge surface, wherein the actuator is configured to change a size of the chamber to force the fluid out from the chamber on a side of the body away from the piezoelectric actuator, and a protective layer on a side of the actuator farther from the chamber, the protective layer having a lower surface and an upper surface opposite to the lower surface, the lower surface covering the actuator, and the upper surface facing a direction away from the chamber and being free from being covered by any additional materials, the protective layer covering the center region, the at least one edge surface, and the at least one corner, wherein a portion of the protective layer covering the center region is sufficiently thin to allow the actuator to contract or expand when the actuator is activated, and wherein the protective layer is formed of a cured organic material, wherein the cured organic material is derived from a resist that is curable at a temperature lower than 240° C.