Swiveling Cube Based 3D Transformable and Auxetic Mechanical Metamaterials

Mechanical metamaterials offer unprecedented control over mechanical properties through mesoscale geometric design. Inspired by the broad applicability of 2D rotating square kirigami, we introduce a new type of flexible 3D mechanical metamaterial based on swiveling cube units. These materials exhibit intrinsic auxetic volumetric deformation enabled by the coordinated pivoting and spinning of interconnected unit cells. We detail the design, prototype fabrication, and characterization of these metamaterials, highlighting their compatible deformation and versatile shape-morphing capabilities. Importantly, we provide a generalized and efficient continuum modeling framework along with computational tools, addressing the challenges of predicting and designing such 3D metamaterials and making the process both feasible and practical. Demonstrative prototypes emphasize programmable volumetric and surface transformations, with potential relevance to applications such as soft robotics or adaptive camouflage. The modular architecture enables reconfigurable assemblies, providing a foundation that could support future scalable and multifunctional metamaterial systems.