Post-fabrication tuning of origami-inspired mechanical metamaterials based on Tachi-Miura Polyhedron

We investigate the reconfigurability and tunability of the tessellation of Tachi-Miura Polyhedron (TMP), an origami-based cellular structure composed of bellows-like unit cells. Lattice-based three-dimensional mechanical metamaterials have recently received significant scientific interest due to their superior and unique mechanical performance compared to conventional materials. However, it is often challenging to achieve tunability and reconfigurability from these metamaterials, since their geometry and functionality tend to be pre-determined in the design and fabrication stage. Here, we utilize TMP's highly versatile phase-transforming and tessellating capabilities to design reconfigurable metamaterial architecture with tunable mechanical properties. The theoretical analyses and experiments with heat processing discover the wide range of the in-situ tunability of the metamaterial – specifically orders of magnitude change in effective density, Young's modulus, and Poisson's ratio – after its fabrication within the elastic deformation regime. We also witness a rather unique behavior of the inverse correlation between effective density and stiffness. This mechanical platform paves the way to design the metamaterial that can actively adapt to various external environments. •A post-fabrication tuning method for origami-based mechanical metamaterials is demonstrated.•A tessellation of Tachi-Miura Polyhedron is manufactured with an efficient method inspired by honeycomb structures.•Heat-processing method is leveraged to achieve the post-fabrication tuning, accompanied by theoretical analyses.•The result shows the wide range of in-situ tunability in effective density, Young's modulus, and Poisson's ratio.