Biomimetic deformable fluidic devices

Deformable fluidic devices are common in biological systems and retain enormous potential for various applications.

Drawing inspiration from the spiral intestines of sharks, we have designed helical pipes – fluidic devices that create asymmetric flow, similar to Tesla valves. We 3D print our designs and optimize the design parameters, achieving greater asymmetry than traditional designs.

The design space of helical pipes (left): The pipe is composed of an external thick tube (remains fixed in this work) with an inner helical structure characterized by a pitch, number of turns, an inner hole and a conical profile with a characteristic angle. 3D printed helical pipes (right): An example of a printed helical pipe. The transverse section reveals the inner structure.

By 3D printing helical pipes from deformable materials, we allow for flow-induced deformations. We show that these deformations increase the asymmetry 7-fold compared to rigid helical pipes. This surprising result calls out for further study to discover the full potential of deformable fluidic devices.

Flow asymmetry in helical pipes: Diodicity (ratio of hydraulic resistance of the two flow directions) range measured for different designs. Rigid helical pipes generate larger asymmetry than traditional designs. Soft pipes induce HUGE asymmetry through flow-induced deformations.

I. Levin, N. Sadaba, A. Nelson, and S. Keller, Asymmetric Fluid Flow in Helical Pipes Inspired by Shark Intestines Proceedings of the National Academy of Science (in Press). arXiv:2407.07354(2024)