Study of Non-Periodical Mechanical Metamaterials: Design and Application

Abstract

We studied a typical mechanical metamaterial with different geometry patterns to demonstrate its effect in wave transmission. An inclusion geometry described by the trigonometric function is employed to generate local resonance under wave propagation. It has been found that the inclusion geometry plays an important role in the bandgap formation and attenuation of sound wave. More importantly, for a hybrid unitcell, the existing of flat and negative-slope bands indicates the translational mode of the dense core, which is critical to understand the wave reflection through non-periodical metamaterials. Furthermore, we propose a concept of velocity tuning of its individual components, which gives rise to local high strain energy, to explain why the absorptivity of sound wave is high. With help of embedded electronic units and dielectric materials, we can realize the active control of the deformation and reconfiguration of the unitcell, thus, to alter its band structure properties. The fabrication of such metamaterials can be realized by plasma etching, laser printing and nanofabrication from centimeter scale to nanometer scale. Therefore, the applications of mechanical metamaterials can be extended from sound filtering in centimeter scale to thermal management in nanometer scale.