Engineers at the University of California San Diego are using bird feathers as a model to develop new adhesives and aerospace materials. The scientists are investigating how a bird can capture air for lift with the underside of a feather, while using the top to block air out for descent.
Research co-authored by Tarah Sullivan, who has a Ph.D. in Materials Science, is the first in nearly 20 years to take a detailed look at the general structure of bird feathers. Using 3D-printed structures, the experts imitated the vanes, barbs, and barbules of a feather to better understand these properties.
Sullivan is part of a team led by Marc Meyers, a professor in the Departments of Nanoengineering and Mechanical and Aerospace Engineering at UC San Diego.
“Professor Eduard Arzt, our co-author from Saarland University in Germany, is an amateur pilot and became fascinated by the ‘bird wing’ problem. Together, we started doing allometric analyses on them and result is fascinating,” said Professor Meyers. “This shows that the synergy of scientists from different backgrounds can produce wonderful new understanding.”
The study revealed that the small structures that connect feather barbs, which are known as barbules, are spaced within 8 to 16 micrometers of one another in all birds species. This means that the spacing must play an important role in flight.
“The first time I saw feather barbules under the microscope I was in awe of their design: intricate, beautiful and functional,” said Sullivan. “As we studied feathers across many species it was amazing to find that despite the enormous differences in size of birds, barbules spacing was constant.”
Sullivan has built prototypes, which she will describe in a follow up paper, to show how various materials designed to mimic a bird feather could be used for aerospace applications as well as adhesives.
“We believe that these structures could serve as inspiration for an interlocking one-directional adhesive or a material with directionally tailored permeability.”
The study is published in the journal Science Advances.
Image Credit: University of California San Diego