Self-deploying origami magnetic membranes with flexible sensors for narrow liquid channels

Miniaturized magnetic membranes have garnered substantial attention in the biomedical field due to their biocompatibility and mechanical properties in recent years. In this study, we explore the self-deployment mechanisms of six origami magnetic membranes with different folding patterns and magnetic polarities. The deployment of the membranes is purely caused by the repelling effect of the internal magnetic fields with different directions without relying on any external magnetic field. And the strength of the internal magnetic field within the membrane directly determines the repelling forces on the pre-deployed region of the magnetic membranes. Our results show that the crimp folded and transversely magnetized membranes can deploy 12.50 times from an original opening size of 2.00 mm in narrow liquid channels within 22 s. Additionally, these membranes exhibit the ability to adaptively deploy in narrow liquid channels with different structures, including L-shaped, V-shaped, and U-shaped at different flow rates. Furthermore, the self-deployable membranes can serve as carriers for flexible and stretchable devices, enabling multi-area deployment through small opening. Integrated with various functional flexible electronics, these self-deployable membranes provide possibilities for innovative applications in the diagnosis and treatment of diseases, and targeted drug delivery.