Decoupling lattice metamaterial directional properties through multi-lattice interpenetration

Innovative design strategies are needed for porous lattices to achieve independent control of directional elasticity, a key requirement for customized anisotropic properties. Traditional methods often couple elastic responses, limiting such control. In this work, we introduce a novel strategy using interpenetrating two-phase structures to control size shrinkage, reducing material continuity and allowing independent stiffness control. This approach provides a new avenue for stiffness decoupling and expands the design possibilities for anisotropic properties. This approach was validated through a series of experiments, theoretical calculations, and finite element analyses. The results confirmed the effectiveness of this approach in achieving independent stiffness control across different directions. Additionally, the proposed strategy demonstrated the ability to adjust the range of directional elastic properties, facilitate design customization, enhance structural energy absorption, and unlock other potential applications. The design enables efficient directional elasticity control and offers potential for broader applications in functional lattice structures.