Durable semi-interpenetrating polymer network containing dynamic boroxine bonds for multi-shape manipulated deformation

Shape-shifting materials with multiple shape manipulation, integrated with durability, shape reconfiguration, shape memory, and reversible deformation, are in high demand for applications in soft robotics, electrical devices, and other fields, but remain a significant technical challenge. In this study, we present a straightforward approach to develop a semi-interpenetrating polymer network (named PVP-VPBA-PEGDMA) crosslinked with dynamic boroxine bonds to address these challenges. The typical PVP-VPBA2-PEGDMA0.2 exhibits high mechanical strength of 38.5 MPa, exceptional self-healing capability (with up to 89.4 % efficiency), and recyclability, ensuring remarkable durability during shape-changing process. Notably, the PVP-VPBA-PEGDMA can be programmatically transformed from 2D sheets into a variety of 3D shapes using humidity-induced solid-state plasticity, which is facilitated by humidity-sensitive dynamic boroxine bonds. The PVP-VPBA-PEGDMA can be folded like paper through origami techniques, and maintain permanent shape configurations, highly suitable for complex shape morphing applications. Moreover, the PVP-VPBA-PEGDMA, in their temporary geometries, can power a model car using shape memory, demonstrating substantial actuation ability and mechanical performance. Leveraging the asymmetric humidity-triggered behavior of the PVP-VPBA-PEGDMA, various functional humidity-responsive devices have been developed, including a crawling robot, a hat, and a conveyor belt with wet sorting capability. Given the programmable shape reconfiguration, shape memory and reversible shape-changing ability of PVP-VPBA-PEGDMA, it opens up numerous potential applications in soft robotics, flexible electronic devices, and intelligent sensors.