Flaps perform essential jobs. From pumping hearts to revving engines, flaps help fluid flow in one direction. Without them, keeping liquids going in the right direction is challenging to do.
Researchers from the University of Washington have discovered a new way to help liquid flow in only one direction — but without flaps. In a paper published Sept. 24 in the Proceedings of the National Academy of Sciences, they report that a flexible pipe — with an interior helical structure inspired by shark intestines — can keep fluid flowing in one direction without the flaps that engines and anatomy rely upon.
Human intestines are essentially a hollow tube. But for sharks and rays, their intestines feature a network of spirals surrounding an interior passageway. In a 2021 publication, a different team proposed that this unique structure promoted one-way flow of fluids — also known as flow asymmetry — through the digestive tracts of sharks and rays without flaps or other aids to prevent backup. That claim caught the attention of UW postdoctoral researcher Ido Levin, lead author on the new paper.
“Flow asymmetry in a pipe with no moving flaps has tremendous technological potential, but the mechanism was puzzling,” says Levin. “It was not clear which parts of the shark’s intestinal structure contributed to the asymmetry and which served only to increase the surface area for nutrient uptake.”
To answer these questions, Levin led a team that included co-authors Sarah Keller and Alshakim Nelson, both UW professors of chemistry, and Naroa Sadaba, a fellow UW postdoctoral researcher. They 3D-printed a series of “biomimetic pipes,” all with interior helices inspired by the layout of shark intestines.
Continue reading the story by James Urton in UW News, September 25, 2024.
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Also published in ScienceDaily and Tech Briefs.