Programmable Pathways for Shape-changing 3D Architected Material

All programmable shape-changing materials aim for a set of functional shapes. However, central to the functionality of various natural and artificial systems is not only the final shape, but also the pathways to reconfiguration, such as protein folding and insect wing deployment. In this study, we introduce a class of three-dimensional architected materials composed of continuous edge-based networks that undergo multi-step reconfiguration in response to external compression. Our system unlocks additional degrees of freedom that are inaccessible to conventional metamaterial designs by embedding folding and cutting into edge-based networks. Through dimension lifting and reduction, the system can reconfigure across distinct topological states caused by the formation of internal self-contacts between the elements of the metamaterial, coupling with behaviors ranging from kinematically indifferent folding to auxetic responses to geometric locking. We realized the metamaterials by using computer-controlled laser cutting of rigid materials. Guided by numerical analysis and physical prototypes, we show the material behaviors and the multi-step pathways can be controlled by the arrangements of the structural elements and rational design of their kinematic compatibility. Given the underlying principles are scalable and material-agnostic by nature, this study opens routes toward spatially adaptive [SS2] [SS3] machines, multifunctional robotic material systems, and morphing architectures.