A MEMS type flow actuated out-of-plane flap apparatus includes a substrate
defining a plane; a duct attached to the substrate, the duct and the
substrate defining a fluid flow channel; and a rotatable flap having a
flow receiving portion and an extension portion. The flow receiving
portion being disposed in the fluid flow channel where, in an actuated
position of the flap, a fluid flow against the flow receiving portion
causes rotation of the flap and movement of the extension portion out of
the plane of the substrate.