Design, Fabrication, and Mechanics of 3D Micro-/Nanolattices

Over the past several decades, lattice materials have been developed and used as engineering materials for lightweight and stiff industrial structures. Recent advances in additive manufacturing techniques have prompted the emergence of architected materials with minimum characteristic sizes ranging from several micrometers to hundreds of nanometers. Taking advantage of the topological design, structural optimization, and size effects of nanomaterials, various 3D micro-/nanolattice materials composed of different materials exhibit combinations of superior mechanical properties, such as low density, high strength (even approaching the theoretical limits), large deformability, good recoverability, and flaw tolerance. As a result, some micro-/nanolattices occupy an unprecedented area in Ashby charts with a combination of different material properties. Here, recent advances in the fabrication and mechanics of micro-/nanolattices are described. First, various design principles and advanced techniques used for the fabrication of micro-/nanolattices are summarized. Then, the mechanical behaviors and properties of micro-/nanolattices are further described, including the compressive Young's modulus, strength, energy absorption, recoverability, and tensile behavior, with an emphasis on mechanistic insights and origins. Finally, the main challenges in the fabrication and mechanics of micro-/nanolattices are addressed and an outlook for further investigations and potential applications of micro-/nanolattices in the future is provided.