Wing Morphing in Insects, Birds and Bats: Mechanism and Function
The great majority of wings are morphing designs with continuously variable planform, camber, or twist: such are the wings of insects, birds, and bats. Indeed, morphing wings may be said to be the norm at the length scales associated with flying animals, while the rigid wing designs that have been favored by engineers are typical only at the largest length scales. It is worth noting in this context that the membranous wings of the largest extinct pterosaurs are currently estimated to have had spans of approximately 10m (Witton and Naish 2008)—comparable to a light aircraft—so it is clear that Nature’s morphing wing designs are workable across a wide range of length scales of current interest to engineers. Just as birds helped inspire the warping wing design of the Wright Flyer, Nature now offers a rich seam of inspiration for a new generation of morphing wing designs across a range of scales of interest to engineers.
In this chapter, we consider wing morphing in its broadest sense as any functional change in wing shape occurring during the course of flight. In flying animals, this encompasses those changes in wing shape that are associated with maneuver control, and those that are associated with the wingbeat cycle. We describe the extent of ...