Exploring multi material mechanical metamaterials

Natural cellular materials exhibit both topological and material optimization. For instance, bone is a composite material of collagen (providing flexibility and toughness) and hydroxyapatite (a mineral that imparts stiffness and strength). The proportion and distribution of these materials vary according to mechanical demands. Inspired by these natural systems, mechanical
metamaterials represent a versatile class of architected materials, where topology has primarily been the focus of design to optimize performance. While the optimization of single-materialll attices is extensively documented in the literature, the integration of multiple lattice structures
within a single framework remains less explored. This study explores this gap by numerically investigating the mechanical performance of combined lattice structures composed of two distinct materials. Recent advances in manufacturing have made it feasible to fabricate multilateral mechanical metamaterials to verify some of these results, paving the way for innovative designs that combine varying material properties with the lightweight and high-performance characteristics of lattices.