Design, Material, Function, and Fabrication of Metamaterials

Recent advances in (multi-material) additive manufacturing (AM, also known as 3D printing) have enabled the fabrication of advanced engineering materials with arbitrarily complex shapes (i.e., geometry or topology at different length scales), as well as spatially distributed material properties (e.g., functionally graded materials). The tight connection between the microarchitecture and multiple material properties has led to the development of (mechanical) metamaterials, a new class of materials with customized properties and multi-functionalities, which have enormous applications in various disciplines, ranging from physics to biomedical and aerospace engineering. Incorporating active materials and mechanisms in the design of metamaterials has provided additional design freedom to employ 4D printing processes to create dynamic 3D printed objects whose properties can change over time (e.g., shape morphing). This special topic aims to capture recent progress in different design schemes and development in fabrication techniques of 3D and 4D printed mechanical metamaterials. Works targeting the development of advanced materials (e.g., architected materials, smart (bio-)materials, active materials such as shape memory polymers), functionalities (e.g., programmability, shape morphing, shape templating, compliant mechanisms), and manufacturing processes (e.g., 3D and 4D processes) are welcome. Interdisciplinary research, including material science, physics, chemistry, biomedical and electrical engineering, are of particular interest.