Twin-inspired design for strengthening and toughening of lightweight lattices in plastic deformation

Energy absorbing lattices applied as protective material suffer premature failure due to shear band propagation. Here, the twin toughening mechanism found in crystals in nano-/microscale is translated to a macroscopic lattice design and is realized by digital light processing. Twin boundaries are formed as sharing plane of two mirrored cells and are enabled by variation of strut thicknesses with a proportion of $$0.617$$ 0.617 in the unit cell. The designed twin boundary can effectively steer crack propagation while dissipating energy resulting in increased specific energy absorption. This effect is amplified by integrating a maximum number of twin boundaries in the material.