Scale-coupling from kirigami cuts controls emergent mechanics in liquid crystal elastomers

Abstract

Conventional materials derive their properties from microscopic composition and arrangement, whereas mechanical metamaterials are defined by mesoscopic structure rather than constituent material. Bridging these paradigms, using macroscopic geometric alterations to orchestrate microscopic degrees of freedom and program mechanics, remains a central challenge. Here, we demonstrate that cuts in anisotropic, responsive solids provide such a connection. Using liquid crystal elastomer (LCE) sheets with kirigami patterns, we reveal that engineering strain through cuts harnesses molecular anisotropy to control emergent mechanics. Similarly, the interplay between cut patterns and the molecular phase transition of LCEs enables soft robotics functionalities such as supersoft grippers with remote actuation and architectures that reversibly morph under temperature variations, behaviors inaccessible to conventional kirigami or LCE sheets alone. LCE kirigami thus establish a new class of multiscale metamaterials in which geometry governs access to microscopic degrees of freedom, to program macroscopic function.