Flow-induced deformation of kirigami sheets

We investigate the deformation in a uniform water flow of thin sheets perforated with parallel cuts. Through combined experiments and theory, we show that deployment is governed by the competition between fluid forces and sheet stretchability, which is prescribed by the cut pattern. Importantly, fluid loading is modulated by the local three-dimensional geometry of pores that open upon stretching. This mesostructure offers a lever to influence macroscopic morphing, notably leading here to asymmetric deformations of symmetric planar sheets. It brings to the fore the kirigami cutting technique as a promising framework for the design of flow-responsive components.