A Dual-Circuit Magnetic Actuation System for Multi-Robot Collaboration in Large-Scale Medical Environments

Untethered miniature robots, after ultra-long-distance transportation to the lesion by continuum robots, can further deliver drugs to the deep fine tissues. Specifically, the magnetic steering continuum robot with the follower-the-leader manner enhances the safety of channel construction, while the magnetically-driven swimming robot with high mobility and maneuverability ensures robust, precise drug delivery. However, it requires an external actuation system capable of covering a large working space and generating diverse magnetic fields to support both robots. Here, a magnetic actuation system excited by dual circuits is developed for the linear combination of constant (up to 13.8 mT) and alternating magnetic fields (up to 93.2 Hz, 11.5 mT) within a large Ø308 mm spherical workspace. This is achieved through the resonance effect of series capacitors and suppressing induced currents through series choke coils. Minimizing conductive materials and optimizing the core and yoke structure reduce the impact of eddy current losses. Through effective temperature management and error compensation, the system can stably generate multiple required magnetic fields over extended periods, navigating the continuum robot through the aortic arch and delivering an untethered miniature swimming robot for precise exploration of the heart's microvasculature.