Multifunctional and Reprogrammable Magnetoactive Graphene Oxide Origami.

Magnetoactive materials, which change shape in response to magnetic fields, hold significant potential for applications in soft robotics, biomedical devices, and morphable structures. However, existing systems often suffer from complex fabrication processes, limited geometric customizability, and inefficient magnetization reprogramming strategies, especially for 3D structures. Here, lightweight magnetic graphene oxide (MGO) bilayer films incorporating hard-magnetic microparticles are introduced to enable fast, precise, and stable shape-morphing under magnetic actuation, including in aqueous environments. The paper-like nature of MGO films allows low-cost and straightforward fabrication of customized structures through post-processing steps such as cutting, folding, and assembly. In addition, the hygroscopic properties of GO introduce a humidity-tunable actuation, offering an extra degree of control. To address the reprogramming challenge, a reversible, high-throughput, and energy-efficient strategy is introduced based on the rearrangements of reusable MGO magnetic stickers, enabling multimodal magnetic shape reconfiguration and functional versatility. Their applications are showcased in in situ mechanical state transitions, sequential logic computing, and soft robot locomotion. Finally, a MGO sensoriactuator is demonstrated capable of magnetic actuation and real-time deformation monitoring, paving the way for closed-loop soft robotic systems. This work presents a sustainable, reconfigurable, and multifunctional strategy for advancing next-generation intelligent magnetoactive soft machines.