Meeting Abstract
Flight feathers maintain a continuous aerodynamic surface during flight despite major wing shape changes. We have discovered that feather microstructures interact between two adjacent feathers when acted on by aerodynamic and wing extension forces. First, aerodynamic forces acting dorsal ventrally press overlapping feathers together. Then, as the bird extends its wings, a lateral extension force pulls the feathers apart. Feather separation is prevented by interlocking microstructures. To understand this microstructure interaction, we studied three pairs of overlapping pigeon, Columba livia, feathers. The rachises of each pair were attached to a 3D printed base with an anatomically accurate spacing. Feathers were interlocked by hand and 3D tomographic images of the interlocked regions were acquired using a Zeiss Xradia 520 Versa X-ray CT machine. Examination of the images revealed that the structures responsible for interlocking overlapping feathers appear to be hooked rami tips on the ventral side of the proximal feather’s leading edge and friction barbules on the dorsal side of the distal feather’s trailing edge. Comparison with SEM images of the same regions revealed that lobate cilia stick up and out of the barbule plane and may be the primary structures that interlock with the hooked rami tips. Further examination of this mechanism could be used to develop bioinspired fasteners.
