A piezoelectric fan includes a piezoelectric actuator patch (110, 210, 310) and a blade (120, 220, 320) attached to the piezoelectric actuator patch. The blade has a hole (121, 127, 221) in it, and a door (122, 128, 222) is adjacent to the hole and attached to the blade (as with a hinge (123, 129, 223)) such that the door is capable of opening and closing.