Design of double negativity elastic metamaterial

A metamaterial model that possesses simultaneously negative effective mass density and negative effective Young’s modulus is proposed in this study. Dispersion curves and dynamic responses of the model are investigated. In the double negative frequency region, it is demonstrated that the phase velocity is negative. In addition, it was found that the band gap region of the metamaterial can be predicted accurately by taking parts of single-unit cell to analyze the steady-state response. The design is also fabricated by a 3D printer.