Different sorts of sharks have intestines with totally different spiral patterns that favor fluid circulate in a single route. Ido Levin and colleagues are recreating these shapes utilizing a 3D printer with a purpose to research the distinctive fluid circulate contained in the spirals. Credit: Image courtesy of Ido Levin
Shark intestines have a novel spiral form that favors fluid circulate in a single route. By studying concerning the workings of this phenomenon, physicists hope to use the rules to robotics and different functions.
Inventor Nikola Tesla patented a sort of pipe that he referred to as a “valvular conduit” in 1920. It was constructed to attract fluid in a single route with none shifting elements or added power and has functions starting from comfortable robotics to medical implants. In 2021, scientists found that sharks’ spiral-shaped intestines work a lot the identical approach, favoring fluid circulate in a single route—from head to pelvis.
Ido Levin, a physicist within the lab of Sarah Keller on the University of Washington, took an interest within the physics circulate of fluid by way of these shark spirals. On Monday, February 20 on the 67th Annual Biophysical Society Meeting in San Diego, California, he’ll current how 3D printing fashions of shark intestines helps them study how these spirals work.
Levin defined that “the researchers of the 2021 study connected a tube to the shark intestines, and put water with glycerin—a very viscous fluid—through these pipes. And they showed that if you connect these intestines in the same direction as a digestive tract, you get a faster flow of fluid than if you connect them the other way around. We thought this was very interesting from a physics perspective… One of the theorems in physics actually states that if you take a pipe, and you flow fluid very slowly through it, you have the same flow if you invert it. So we were very surprised to see experiments that contradict the theory. But then you remember that the intestines are not made out of steel—they’re made of something soft, so while fluid flows through the pipe, it deforms it.”
To research the fluid dynamics by way of spiral pipes, Levin and Keller collaborated with their colleagues within the Nelson Group on the University of Washington to create soft, 3D structures that mimic aspects of the shark intestines. “15 or 20 years ago, it was impossible to try and reconstruct these shapes in manmade materials,” Levin said. When they used a rigid material to 3D print the shapes, there was no difference in fluid flow in one direction or the other. However, printing the shapes using a softer elastomer led to faster fluid flow in one direction. Using these 3D-printed structures, the team is studying how the radius, pitch, and thickness of the inner structure impacts the fluid flow. With the softer materials, they can also study the coupling between flow rate and how the pipe deforms. Understanding these parameters will help in engineering similar structures that can be used for things like soft robotics.
Up until recently, robots have been made with rigid materials and hinges. But using soft materials that can deform in different ways, like an octopus does, opens up a whole world of possibilities, Levin explains, “this is one step forward in trying to understand the basic mechanics of the interaction between membranes and flow.” One day, this seemingly simple system could control industrial or medical devices.
