Scientists at Southampton University have revealed in a new study that feather shafts are made of a multiple layers of keratin, a fibrous material similar in construction to carbon fibre.
Since their appearance over 150 million years ago, feather shafts or rachises have evolved to become some of the lightest, strongest and most fatigue resistant natural structures. Until now relatively little work has been done on their morphology, especially from a mechanical perspective and never at the nanoscale.
Scientists at the University were the first to use a material testing technique called nano-indentation on the feathers from three different bird species which revealed the number, proportion and relative orientation of rachis layers is not fixed, as previously thought, and varies according to flight style.
Christian Laurent, from Ocean and Earth Science at the University of Southampton, lead author of the study, says:
We started looking at the shape of the rachis and how it changes along the length of it to accommodate different stresses. Then we realised that we had no idea how elastic it was, so we indented some sample feathers.
On an engineering level the team hope to apply their findings in materials science to yacht masts and propeller blades, and to apply the aeronautical findings to build better micro air vehicles in a collaboration engineers at the University.