Geometry-Driven Performance In 3D Printing Bio-Based Chiral and Antichiral Metamaterials: Experimental and Numerical Evaluation

This study examines the mechanical properties of trichiral (TC), antitrichiral (ATC), and reentrant antitrichiral (ATCR) networks when subjected to tensile, compression, and bending loads. The experimental data indicate that tensile properties are governed primarily by geometry, while compressive and bending performance are also influenced by relative density. The trichiral network shows the highest tensile stiffness, with Young's moduli of 18 MPa (single-cell) and 150 MPa (twocell). The antitrichiral and reentrant antitrichiral geometries exhibit lower stiffness (120 MPa and 40 MPa, respectively) but display negative Poisson's ratios, indicating auxetic behavior. In compression, the antitrichiral network yielded the best results with a compression modulus of 105 MPa and showed energy absorption up to 40% greater than the other geometries. Bending tests demonstrate that the antitrichiral sandwich structure carries a larger load due to the higher density of the structure, despite some minor variation due to 3D printing. These results demonstrate that geometry, rather than the density, governs mechanical performance of architected materials. The trichiral topology is excellent for a lightweight, high-stiffness design, while the antitrichiral design provides superior energy absorption.