Additive Manufacturing and Characterization of Structural and Multi-functional Metamaterials

ABSTRACT

Materials featuring three-dimensional microarchitectures exhibit various extreme functional properties, including negative thermal expansion, high-efficiency electromechanical conversion, ultrahigh stiffness and damage tolerance. Their remarkable properties are dominated by both the parent material and their microarchitecture and thus, they are commonly referred to as architected metamaterials. The rapid progress in 3D printing techniques has enabled the creation of architected metamaterials and unfolded many potential applications. However, the characterization and applicability of these metamaterials are significantly limited by the manufacturing scalability. Additionally, most currently available 3D printing methods only handle single structural materials, and it remains a challenge to 3D print multifunctional architected metamaterials. This presentation will focus on 3D printing techniques that address these key challenges, the investigation of elusive metamaterial properties, as well as the design and manufacturing of multifunctional architected metamaterials. The talk will first introduce a large-area projection stereolithography system capable of manufacturing submeter scale objects with micro-scale architectures, which enables the investigation of size effect in high-temperature ceramics and fracture toughness of mechanical metamaterials. This talk will then demonstrate the design and multi-material additive manufacturing of a series of robotic metamaterials that seamlessly integrate piezo-active, structural and conducting architectures. These robotic metamaterials can directly serve as micro-robots and achieve multi-degree-of-freedom motion, proprioception as well as responses to remote stimuli. All these works contribute to the understanding of the process-structure-property relationship of architected metamaterials as well as the creation of future intelligent materials and devices.