Kirigami Design and Modeling for Strong, Lightweight Metamaterials

Kirigami is the art of paper cutting, and it is emerging as an elegant design and manufacturing solution in mechanical metamaterials. Currently, the majority of kirigami designs focus on shape-morphing, but there is little attention on the remarkable mechanical properties they can produce: high strength to weight ratio where they can bear thousands of times of their own weight. This paper proposes a kirigami-based, strong, yet lightweight metamaterial, which is created by folding pop-up and pop-down from a checkerboard pattern with blocks. To transform the kirigami metamaterial into arbitrary objects, the challenge lies in how to automatically design the kirigami folding to approximate the outline of the object. Herein, a computational model that is based on deploying discretized objects onto a planar sheet is proposed. Additionally, to achieve high strength, a glue-free connector that can lock the collocated cuts in the folded configuration is designed. The standard compression tests show that the kirigami metamaterial, weighing 12.05 g, can carry 346.4 N payloads. Meanwhile, six examples of curved surfaces are prototyped to verify the shape transforming capability of the proposed kirigami metamaterial. This study paves the way towards using the kirigami technique for weight reduction in industrial applications.