Harnessing nature's design: enhancing buckling strength in lattice structures inspired by Lychniscosida sponge

Truss-based lattice structures provide excellent strength-to-weight performance but are particularly susceptible to elastic buckling at low relative densities. In this study, naturally-occurring lightweight truss-like structures found in the skeletal framework of the deep-sea sponge Neoaulocystis Zitelli were investigated as bioinspired models to explore their potential for improving buckling strength of truss based lattice structures. A three-dimensional lattice was reconstructed from SEM-derived dimensional data and analysed for stability using a linear buckling analysis. The resulting instability modes revealed localised structural vulnerabilities, prompting an enhancement through architectural refinement via topological simplification, yielding three derivative configurations: simple cubic, octahedral, and lantern, and through the geometric tuning of strut curvature, relative diameters, and connector aspect ratios. All designs were fabricated using the LCD-based 3D printing technique, simulated using finite element simulations, and experimentally tested under uniaxial compression at a relative density of 5%. The optimised bioinspired configuration shifted buckling from a local to a more stable global mode resulting in a 22% increase in critical buckling stress compared to the baseline simple cubic design. These findings underscore the promise offered by bioinspired, buckling-driven design methods for designing robust, lightweight lattice materials for engineering applications.