The shark spiral valve — the helical intestinal structure found in elasmobranch fishes — solves a fundamental engineering optimisation problem: maximising surface area for contact and transfer in minimum organ length. Levin et al. (2024) confirmed that this biological structure functions as a passive one-directional flow device — a biological equivalent of the Tesla valve — enabling directional fluid flow without moving parts through geometry alone. This paper documents the independent conception of the shark spiral valve geometry as a thermal and biological engineering framework, with a Windows file modification date of November 12, 2023 — predating that publication by ten months. Four specific engineering applications are proposed: (1) heat exchanger, (2) two-chamber boiler, (3) cooling plate and heat pipe, and (4) external mechanical nutrient absorber for Short Bowel Syndrome patients. The paper further proposes that the biological spiral valve geometry — optimised by millions of years of evolutionary pressure — may offer manufacturing and performance advantages over mathematically-derived spiral and Tesla valve geometries in specific contexts.
Budinny V (Sun,) studied this question.