Geometric design classification of kirigami-inspired metastructures and metamaterials

In recent years, kirigami - the ancient art of paper-cutting - has been widely studied by scientists and engineers in various fields such as structural mechanics, materials, optics, electronics, robotics, and bioengineering. Kirigami is a combination of slits and creases; therefore, a kirigami structure has a cutting step that is not involved in making an origami structure. In general, a kirigami structure starts from a continuous planar sheet, forms a new shape by cutting or carving, and finally acquires a new structural configuration by stretching, folding, or other external stimuli. Kirigami is considered to be an innovative and effective method for advanced three-dimensional micro- and nano-manufacturing by providing different fabrication strategies through cutting and folding thin sheets. Furthermore, kirigami is generally used as a technique to make (meta)materials and (meta)structures with extraordinary properties such as negative Poisson's ratio. In doing so, a given material/structure is transformed into a metamaterial/metastructure with properties which do not exist in the initial material/structure. In this paper, from the perspective of geometric design, kirigami patterns are categorized into two groups: (1) cut-only kirigami, and (2) cut-and-fold kirigami. Moreover, the patterns are classified into five categories as follows: fractal cut, ribbon, lattice, zigzag, and closed-loop kirigami. Physical models are made and presented to demonstrate the design and geometric properties of these kirigami patterns. Finally, this review summarizes the current developments in kirigami-inspired metastructures and metamaterials and concludes with a future outlook of their potential applications in science and engineering.

Automated summary

Kirigami, the ancient art of paper-cutting, has been widely studied in recent years by scientists and engineers in various fields. It is considered as an innovative method for advanced 3D micro- and nano-manufacturing, providing different fabrication strategies through cutting and folding thin sheets. In this paper, kirigami patterns are categorized into two groups and classified into five categories, demonstrating unique design and geometric properties suitable for metamaterials and metastructures.