Figure 2.

New class of hinged-3D metamaterials with giant and strain-independent Poisson’s ratios. (a) 3D printed and 3D-assembeled samples of unit cells with giant and constant Poisson’s ratios. The different geometry and material topology of the prepared unit cells are summarized in Table 1. (b) Measured Poisson’s ratios (${\nu }_{xy}$ and ${\nu }_{xz}$) of the 3D printed samples. Experimental and numerical results are compared. (c) The transverse strains, ${\mathit{ϵ}}_y$ and ${\mathit{ϵ}}_z$, as functions of the applied longitudinal strain, ${\mathit{ϵ}}_x$, for a material sample with $L=29.4\mathrm{mm}$, $W=39.33\mathrm{mm}$, and $T=52.18\mathrm{mm}$. The experimental results (symbols) are compared to the results of the numerical model (solid lines). Curves of the linear fitting to the experimental results are represented by dashed lines.