Engineering Translation of Biological Hydrostatic Skeleton Principles: A Design Framework for Large-Scale Hydraulic Structures

Biological hydrostatic skeletons use pressurized fluid compartments constrained by tension-resistant membranes to provide structural support in soft-bodied invertebrates. Evolution has optimized these systems over 500 million years. While soft robotics has successfully applied hydrostatic principles at the centimeter scale, their translation to large-scale civil infrastructure remains largely unexplored. This paper presents a biomimetic design framework for adapting hydrostatic principles to engineering applications ranging from flood barriers to water storage.We identify four convergent biological design rules extracted from earthworms, jellyfish, and sea anemones: (1) segmented compartmentalization for damage isolation, (2) elastic coupling for load redistribution, (3) hierarchical organization for scalability, and (4) topological redundancy for graceful degradation. By systematically translating these principles, we propose a Pressure Differential Architecture (PDA) that utilizes water as the primary structural element.We demonstrate that synthetic analogs to biological tissues—Natural Rubber Latex (NRL) for body walls, elastic adhesives for connective septa—can theoretically replicate biological performance metrics, including damping ratios (ζ ≈ 0.50–0.63) and force transmission efficiencies (>99%). Furthermore, we analyze how engineered hydrostatic systems can circumvent the allometric scaling constraints (the square-cube law) that limit biological organism size, by decoupling pressurization from metabolic muscle through external pressure sources. This work establishes a methodology for translating evolutionary solutions to infrastructure challenges.