Another stretching-dominated micro-architectured material, shellular

Abstract: At a density lower than 10⁻¹?g/cc, Microlattice and Nanolattice become vulnerable and tend to fail because of the early local buckling concentrated at the connections between the hollow trusses that compose them. In contrast, a Shellular, in the form of a triply periodic minimal surface (TPMS), has a constant curvature over the entire shell without stress concentration and maintains a stretching-dominated deformation down to a much lower density. To realize the full potential of the TPMS Shellular, a high-precision technique is used for forming a template that can be used to fabricate the Shellular. Specifically, polymer beads are arranged in a regular pattern, resembling a crystalline structure and then naturally transformed into a TPMS shape of the template by means of a special chemical process, named Han’s treatment. The in situ observation under compression reveals that the smooth shell with a constant curvature of the TPMS Shellular effectively suppresses the local deformation and delays the transition to the elastic buckling, resulting in such high mechanical properties. Moreover, this novel technique can be extended down to a cell size of a few micrometer scales, showing its vast range of scalability.

https://doi.org/10.1016/j.mattod.2019.05.018