Ultralight, ductile metal mechanical metamaterials with super elastic admissible strain (0.1)

Mechanical metamaterials are architectured cellular materials with unusual properties. Herein we report another type of metal mechanical metamaterials—their elastic admissible strain (EAS) is on the order of 0.1, compared to about 0.01 for common metallic materials. Four conditions are required for a metal mechanical metamaterial to achieve this super EAS: (i) bending-dominated deformation; (ii) low density; (iii) an appropriate lattice topology, and (iv) an intrinsically high EAS for the lattice strut constituent material. The findings of this work extend perspectives on metal mechanical metamaterials.