PIEZOELECTRIC METAMATERIALS AND WAVE CONTROL: STATUS QUO AND PROSPECTS

Elastic wave metamaterial is a kind of artificially designed periodic structure. It has received extensive attention due to its special mechanical properties and has shown valuable and unique application prospects in both military and civilian fields. Actively or passively controlling the characteristics of elastic wave metamaterials according to the needs can endow them with stronger applicability. There are lots of tuning ways, among which using piezoelectric materials is a convenient, fast, high-precision, small-sized and low-cost method. In this article, we first briefly introduced the basic aspects of elastic wave metamaterials, tunable metamaterials, piezoelectric materials and several commonly used shunt circuits. Then, according to the different application forms of piezoelectric materials in elastic wave metamaterials, they are divided into two categories: in the first category, the piezoelectric material constitutes the major structure or acts as a part of the major structure; in the second category, the piezoelectric material is used in the form of a spring or a patch attached to the surface of the major structure or embedded in the structure, acting as an actuator or/and a sensor. We elaborated on the research topics and the development history of the two categories of piezoelectric elastic wave metamaterials, related to band gap regulation, waveguide, negative refraction, super transmission, topological state, cloak as well as shunt circuits. Finally, we summarized the research deficiencies of piezoelectric elastic wave metamaterials and outlined corresponding future research prospects.