Programmable Deformation of Metallic Kirigami

Kirigami, the Japanese art of paper cutting, has gained considerable attention for its ability to create complex 2D and 3D deployable structures. Kirigami principles have enabled the development of innovative structures with diverse applications in fields such as aerospace, robotics, and flexible electronics. The mechanical response of a kirigami structure is largely a function of its cut pattern; by strategically imposing a pattern of cuts, it is possible to achieve a desired mechanical response. While many studies have explored the deformation mechanics of kirigami through analytical, numerical, and experimental investigations, most studies have focused on elastic materials with uniform cut patterns. In this work we investigate the role of plasticity and cut pattern on the mechanical behavior of parallel-cut kirigami using a combination of experiments, finite element modeling, and analytical calculations. When cuts are imposed into an initially flat elastic material and then subjected to in-plane extension, the entire kirigami is observed to deform uniformly. We show that introducing plasticity results in a sequential buckling deformation through the creation of a propagating instability. Additionally, we show how this sequential buckling deformation can be controlled by introducing nonuniform cut patterns. Across all studied configurations, strong agreement was found between analytical predictions, simulations, and experiments. These insights lay the groundwork for designing advanced kirigami systems with tailored mechanical properties.