Customized deformation behavior of morphing wing through reversibly assembled multi-stable metamaterials

The geometry of multi-stable metamaterials, will change by the transition from one stable state to another. Shape morphing wings consisted of multi-stable metamaterials have capability to deform as desired, attributed to the programmable mechanical properties of architectured materials. In this study, to fabricate large-scale shape morphing structures, multi-stable unit cells with reversible connections were designed, printed and assembled. The mechanical properties and deformation capability were examined for multi-stable metamaterials with different geometrical parameters (e.g. width, thickness of beams). The deformation sequence for one assembled column consisting of identical multi-stable unit cells was found unpredictable, but could be tailored into a predictable manner by slightly adjusting beam geometry. To realize the customized deformation profile, the overall design domain of shape morphing structures was discretized into independent sub-regions. By enforcing deformation on sub-regions via the precise control of mechanical actuators that fixed with corresponding columns, the assembled shape morphing structures formed the targeted deformation. Also, the deformation feasibility was also demonstrated after incorporating voids or nondeformable functional elements within the assembled metamaterials platform. This study had provided practical solution for the design and fabrication of metamaterial-based shape morphing structures, and would shed light on future innovation of morphing aircraft.