Bioinspired crescent-shaped textures from the chela of Procambarus clarkii for reducing pipe penetration resistance in muddy environments

Penetration resistance during pipe installation in muddy sediments significantly limits operational efficiency and increases energy consumption in offshore engineering, cable laying, and deep-sea sampling. Inspired by the burrowing capability of Procambarus clarkii, this study investigates the crescent-shaped concave–convex microstructures on its chela and evaluates their feasibility for reducing penetration resistance. Six textured pipe configurations were designed and fabricated via 3D printing, and comparative penetration experiments were conducted in mud. Results demonstrate that all bioinspired textured surfaces reduce resistance relative to smooth pipes, with the concave–convex composite texture yielding optimal performance. The resistance reduction efficacy depends strongly on texture orientation and penetration velocity: when the crescent sharp angle aligns with the flow direction, mimicking the natural texture, the maximum reduction reaches 49% at 11 mm/s. Numerical simulations using the Bingham-Papanastasiou constitutive model, combined with flow visualization experiments, reveal a synergistic mechanism: concave structures reduce wall–liquid contact area and thus lower frictional resistance, while convex protrusions induce localized shear-thinning, promoting a low-viscosity lubricating layer. This medium-dependent effect is effective in mud but absent in sand. This study provides a passive, nature-inspired strategy for energy-efficient mud transport, with direct implications for tribological design of soil-engaging and penetrating components.