Metamaterial electromagnetic wave absorbers and devices: Design and 3D microarchitecture

Metamaterials refer to a class of artificial composite structures with supernormal physical properties that natural materials do not have. The emergence of metamaterials has opened up new research directions for classical electromagnetic theory and made it possible to manipulate electromagnetic waves effectively. One of most important applications of metamaterials is metamaterial absorbers (MMAs). The properties of MMAs depend on the material composition, cell size and structure, which could often achieve "perfect" absorption through reasonable design. This review starts with the development of MMAs and describes the status of this absorber, then mainly focuses on bionic design and new artificial design. Specifically, it is to draw inspiration from natural plants and animals, design novel structures to get better absorbing properties. Furthermore, the artificial design can achieve the optimize absorption capacity as well as absorption bandwidth. What's more, this review summarizes the 3D printing technology to prepare MMAs that are different from traditional printed circuit board technology. The MMAs produced by 3D printing technology can prepare more complex shapes, and has light weight and better absorbing properties.