Fig. 3: Different combinations of designs with extreme mechanical properties.

These designs are selected from each group of the unit cells (i.e., a re-entrant structure with a highly negative Poisson’s ratio, a honeycomb structure with a highly positive Poisson’s ratio, and an orthogonal structure with a high value of the elastic modulus). a The mechanical properties of two four-tile structures with non-rotated and rotated tiles and the distribution of the von Mises stresses in these lattice structures. These multi-material 3D printed specimens were mechanically tested in both the 1- and 2-directions under 3% tensile strain and the experimental results were compared with the FE simulation results (Table 1). b The mechanical properties of nine-tile combinations and the von Mises stress distribution in these combinations. These multi-material 3D printed specimens were mechanically tested in both the 1- and 2-directions under 3% tensile strain, and the experimental results were compared with the FE simulation results (Table 1).