Fred Ruhe
Well-known member
Laura Y. Matloff, Eric Chang, Teresa J. Feo, Lindsie Jeffries, Amanda K. Stowers, Cole Thomson & David Lentink, 2020
How flight feathers stick together to form a continuous morphing wing.
Science 367(6475): 293-297
DOI: 10.1126/science.aaz3358
Abstract: https://science.sciencemag.org/content/367/6475/293
Wing shapes take flight
Birds can dynamically alter the shape of their wings during flight, although how this is accomplished is poorly understood. Matloff et al. found that two mechanisms control the movement of the individual feathers. Whenever the skeleton moves, the feathers are redistributed passively through compliance of the elastic connective tissue at the feather base. To prevent the feathers from spreading too far apart, hook-shaped microstructures on adjacent feathers form a directional fastener that locks adjacent feathers. These features are found across a range of bird sizes; however, because the detachment of the hooks is noisy, they are notably absent in silent fliers, such as barn owls.
Abstract
Variable feather overlap enables birds to morph their wings, unlike aircraft. They accomplish this feat by means of elastic compliance of connective tissue, which passively redistributes the overlapping flight feathers when the skeleton moves to morph the wing planform. Distinctive microstructures form “directional Velcro,” such that when adjacent feathers slide apart during extension, thousands of lobate cilia on the underlapping feathers lock probabilistically with hooked rami of overlapping feathers to prevent gaps. These structures unlock automatically during flexion. Using a feathered morphing wings robust to turbulence. We found that the hooked microstructures fasten feathers across bird species except silent fliers, whose feathers also lack the associated Velcro-like noise. These findings could inspire innovative directional fasteners and morphing aircraft.
Free pdf: https://science.sciencemag.org/content/sci/367/6475/293.full.pdf
Enjoy,
Fred
How flight feathers stick together to form a continuous morphing wing.
Science 367(6475): 293-297
DOI: 10.1126/science.aaz3358
Abstract: https://science.sciencemag.org/content/367/6475/293
Wing shapes take flight
Birds can dynamically alter the shape of their wings during flight, although how this is accomplished is poorly understood. Matloff et al. found that two mechanisms control the movement of the individual feathers. Whenever the skeleton moves, the feathers are redistributed passively through compliance of the elastic connective tissue at the feather base. To prevent the feathers from spreading too far apart, hook-shaped microstructures on adjacent feathers form a directional fastener that locks adjacent feathers. These features are found across a range of bird sizes; however, because the detachment of the hooks is noisy, they are notably absent in silent fliers, such as barn owls.
Abstract
Variable feather overlap enables birds to morph their wings, unlike aircraft. They accomplish this feat by means of elastic compliance of connective tissue, which passively redistributes the overlapping flight feathers when the skeleton moves to morph the wing planform. Distinctive microstructures form “directional Velcro,” such that when adjacent feathers slide apart during extension, thousands of lobate cilia on the underlapping feathers lock probabilistically with hooked rami of overlapping feathers to prevent gaps. These structures unlock automatically during flexion. Using a feathered morphing wings robust to turbulence. We found that the hooked microstructures fasten feathers across bird species except silent fliers, whose feathers also lack the associated Velcro-like noise. These findings could inspire innovative directional fasteners and morphing aircraft.
Free pdf: https://science.sciencemag.org/content/sci/367/6475/293.full.pdf
Enjoy,
Fred
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