Chirality manipulation of 3D printed gyroidal scaffolds towards mechanical properties enhancement

As the most appealing triply periodic hyperbolic surface, the gyroid (G) processes large strength-to-weight ratio and high energy absorption efficiency due to the distinctive energy distribution within its continuous saddle-shape surface. However, the structural complexity of G surface blocks the way in deeply understanding the origin of its mechanical responses. Particularly, the role of the chirality of gyroid works in its mechanical performance remains an unresolved issue. Herein, we investigate the influence of the topological structure and interlocking chiral geometry on the mechanical properties of G-related structures modeled from chirality manipulation and symmetrical modulation. Homochiral and racemic G structures from single to quadruple interlacing gyroidal networks were designed to experimentally evaluate their uniaxial compression mechanical properties, and their deformation mechanism was further conducted from finite element simulations. Our results showed that both the numbers and chirality degree of the networks significantly affect the mechanical properties of the materials. In particular, the spatially equally distributed left and right networks promote stronger mechanical strength due to a more uniform dispersion of mechanical stress. This chiral structural design strategy emphasizes the significance of structural spatial symmetry in mechanical regulation and opens up new horizons for the design of novel mechanical structures.