Coordinated position–posture regulation framework for intestinal targeted drug delivery using a rotating-field cylindrical microrobot

Magnetic microrobots hold promise for minimally invasive drug delivery within the intestinal tract. Current systems predominantly rely on permanent-magnet actuation, which can regulate both position and orientation but inherently moves the microrobot by dragging it along tissue surfaces. The resulting nonuniform magnetic pulling forces increase friction at the intestinal wall and may cause mucosal irritation or even injury. To overcome these safety limitations, we develop a closed-loop regulation framework that achieves synchronous position–posture control entirely within a rolling paradigm driven by a uniform rotating magnetic field. The rotating field enables gentle, low-friction rolling, while posture-constrained approach trajectories and real-time vision feedback allow the microrobot to autonomously align and navigate toward designated lesion sites. Full-process tests in an intestinal-like phantom confirm that the system maintains submillimetre navigation accuracy, docks reliably at multiple release sites, and performs smooth autonomous retrieval along the planned path. Together, these capabilities establish a reproducible and low-stress control strategy suitable for safe and repeatable intestinal drug delivery.