Programmable Light-Driven Liquid Crystal Elastomer Kirigami with Controlled Molecular Orientations

Programmable soft materials have shown applications in artificial muscles, soft robotics, flexible electronics, and biomedicines due to their adaptive structural transformations. As an ordered soft material, directional shape changes of liquid crystal elastomer (LCE) can be easily achieved via external stimuli thanks to its anisotropic elasticity. However, harnessing the interplay between molecular ordering, geometry, and shape morphing in this anisotropic material to create programmable and complex shape changes remains a challenge. Here, by integrating the concepts of kirigami or Chinese paper cutting "JianZhi" in the light-actuated LCE encoded with controlled molecular orientations, various complex 3D shape morphing behaviors are demonstrated. Versatile combinations of fundamental shape changes such as bending, folding, twisting, and rolling are enabled by fine-tuning the molecular orientations and geometries in the monolithic LCE kirigami. Furthermore, various functions such as fluttering of the Chinese crane bird "QianZhiHe," arbitrary directional locomotion in the annulus and linear locomotion in the complex Chinese character are also realized. These complex, fast-response, untethered, remote, reversible, and programmable shape morphologies actuated in a monolith of LCE kirigami will open opportunities in soft robotics and smart materials.