The Wikipedia "Flap (aircraft)" entry includes the following cryptic note:
Anyone know the source of this comment or an example of this type of flap?A modern variation on the plain flap exploits the ability of composites to be designed to be rigid in one direction, while flexible in another. When such a material forms the skin of the wing, its camber can be altered by the geometry of the internal supporting structure, allowing such a surface to be used either as a flap or as an aileron. While most currently use a complex system of motors and actuators, the simplest such installation uses ribs that resemble bent carrots - when the bend is nearly horizontal, there is no deflection, but when the carrot is rotated so the bend is downward, the camber of the airfoil is changed in the same manner as on a plain flap.[citation needed]