Three-dimensional anti-chiral auxetic metamaterial with tunable phononic bandgap

Auxetic metamaterials have received wide attention due to their idiosyncratic physical properties. In this paper, experiments and simulations were performed to study the mechanical and acoustic properties of a 3D anti-chiral auxetic metamaterial subjected to quasi-static loading. The results shows that Poisson's ratio of the designed metamaterial can be changed from -0.45 to 0.35 with different cell parameters. Acoustic tests show that the designed metamaterial provides an ultra-wide phononic bandgap and exhibits outstanding wave attenuation properties. By applying rational tensile/compression force, the bandgap is widened/narrowed, which indicates the tunability of the bandgap through deformation. Moreover, the bandgap tuning is through all high symmetry points in the Brillouin zone due to the iso-auxeticity of the metamaterial. This study provides a possible way for controlling the bandgap with the deformable metamaterial.