Vine Robots With Magnetic Skin for Surgical Navigations

Drawing inspiration from natural growth and movement strategies, vine robots possess exceptional passive shape-forming abilities, enabling them to deform around obstacles. However, an intrinsic lack of active steering limits their capacity to control their growth trajectory. This letter considers the external manipulation of such robots through the utilization of magnetically active materials embedded within the vine robot's skin. This results in a completely flexible, steerable, growing structure that can be actuated via the application of external magnetic fields and field gradients. We explore the principles of magnetically-guided vine robots and provide empirical evidence highlighting the efficacy of our proposed magnetic steering methodology. Due to the inverted internal structure, careful design of the magnetization direction of the robot has to be considered. We propose an orthogonal magnetization strategy that successfully preserves a net positive magnetization. We focus on a vine robot of 8 mm in diameter, constructed from a polyethylene substrate coated with a silicone layer embedded with magnetic micro-particles. We demonstrate the ability of our robots to navigate complex environments and steer around large obstacles in a shear free manner via the simultaneous control of both the magnetic field and the growing pressure. Finally, we demonstrate our robot by performing the selective navigation of multiple bifurcations within a bronchial tree phantom.