Submillimeter Multifunctional Ferromagnetic Fiber Robots for Navigation, Sensing, And Modulation.

Small-scale robots capable of remote active steering and navigation offer great potential for biomedical applications. However, the current design and manufacturing procedure impede their miniaturization and integration of various diagnostic and therapeutic functionalities. Here, we present submillimeter fiber robots that can integrate navigation, sensing, and modulation functions. These fiber robots are fabricated through a scalable thermal drawing process at a speed of 4 meters per minutes, which enables the integration of ferromagnetic, electrical, optical, and microfluidic composite with an overall diameter of as small as 250 μm and a length of as long as 150 m. The fiber tip deflection angle can reach up to 54 o under a uniform magnetic field of 45 mT. We also demonstrate that these fiber robots can navigate through complex and constrained environments, such as artificial vessels and brain phantoms. Moreover, we utilize Langendorff mouse hearts model, glioblastoma micro platforms, and in vivo mouse models to demonstrate the capabilities of sensing electrophysiology signals and performing localized treatment. Additionally, we demonstrate that the fiber robots can serve as endoscopes with embedded waveguides. These fiber robots provide a versatile platform for targeted multimodal detection and treatment at hard-to-reach locations in a minimally invasive and remotely controllable manner. This article is protected by copyright. All rights reserved.