Patent ID: 7550901

Claim:
A piezoelectric fan comprising: a piezoelectric actuator patch; and a blade attached to the piezoelectric actuator patch, wherein the blade comprises: a hole; and a door adjacent to the hole, the door attached to the blade with a hinge capable of allowing the door to open and close, wherein: the hole is a first hole of a plurality of holes in the blade; the door is a first door of a plurality of doors attached to the blade; each one of the plurality of doors is, like the first door, adjacent to one of the plurality of holes; each one of the plurality of doors is, like the first door, attached to the blade with a hinge capable of allowing the door to open and close; the first door of the plurality of doors is made of a first material; and a second door of the plurality of doors is made of a second material that is different from the first material.