Abstract：
Shape morphing in bistable kirigami enables remarkable functionalities appealing to a diverse range of applications across the spectrum of length scale. At the core of their shape shifting lies the architecture of their repeating unit, where highly deformable slits and quasi-rigid rotating units often exhibit multiple symmetries that confer isotropic deployment obeying uniform scaling transformation. In this work, symmetry breaking in bistable kirigami is investigated to access geometric frustration and anisotropic morphing, enabling arbitrarily scaled deployment in planar and spatial bistable domains. With an analysis on their symmetry properties complemented by a systematic investigation integrating semi-analytical derivations, numerical simulations, and experiments on elastic kirigami sheets, this work unveils the fundamental relations between slit symmetry, geometric frustration, and anisotropic bistable deployment. Furthermore, asymmetric kirigami units are leveraged in planar and flat-to-3D demonstrations to showcase the pivotal role of shear deformation in achieving target shapes and functions so far unattainable with uniformly stretchable kirigami. The insights provided in this work unveil the role of slit symmetry breaking in controlling the anisotropic bistable deployment of soft kirigami metamaterials, enriching the range of achievable functionalities for applications spanning deployable space structures, wearable technologies, and soft machines.
摘要：
双稳态kirigami中的形状变形可实现显着功能，可在长度范围内吸引各种应用。它们形状转变的核心在于它们重复单元的结构，其中高度可变形的狭缝和准刚性旋转单元通常表现出多种对称性，这些对称性赋予各向同性的部署服从均匀的缩放变换。在这项工作中,研究了双稳态kirigami中的对称性破坏，以获得几何挫败感和各向异性变形，在平面和空间双稳态域中实现任意缩放的部署。通过对其对称性的分析，并结合半解析推导的系统研究，数值模拟，和弹性kirigami床单的实验，这项工作揭示了狭缝对称之间的基本关系，几何挫折，和各向异性双稳态部署。此外，在平面和平面到3D演示中利用了不对称的kirigami单元，以展示剪切变形在实现目标形状和功能方面的关键作用，迄今为止，均匀可拉伸的kirigami无法实现。这项工作提供的见解揭示了狭缝对称破坏在控制软kirgami超材料的各向异性双稳态部署中的作用，丰富了跨越可部署空间结构的应用的可实现功能的范围，可穿戴技术，软机器。
