Between 1999 and 2020, gastrointestinal cancers were responsible for over three million deaths, emphasizing the critical role of minimally invasive surgical techniques like Endoscopic Submucosal Dissection (ESD) in managing such life-threatening conditions. ESD, which dissects the connective tissue between the mucosal and muscular layers using an electrosurgical knife connected to an endoscope, requires a constant traction force to stabilize tissues and expose underlying anatomical structures. This paper introduces a miniature magnetic flexible robot, actuated by a permanent magnet on a robotic manipulator, designed to enhance ESD by providing traction forces consistently on lesions. The robot was fabricated by casting magnetic silicone composites, and its safe deployment through the endoscope instrument channel was successfully demonstrated, avoiding tissue contact. Experiments in a rubber intestine model validated the feasibility of providing constant traction and 2 DOF orientation control via the robot, allowing real-time fine-tuning of the force direction. This reduces the difficulty and improves the precision and safety of ESD. This research presents a practical method for achieving stable force output in medical miniature robots, particularly in gastrointestinal procedures.

This paper deals with hopping motion analysis of spherical robot with a typical impact condition like 'superball'. A horizontal velocity of super ball after an impact depends on the angular velocity before the impact where it doesn't slip at the contact point. Our robot model consists of an elastic spherical shell with such an impact condition and of an internal rotary input. Assuming the perfectly elastic impact in a vertical direction, a feedback control strategy for generating the horizontal velocity after an impact by the rotary input during flying phase is derived. Simulation results show that some hopping motion is achieved by the proposed method. In addition, this paper shows the possibility and necessary condition that a climbing motion with impacts against two parallel vertical planes is achieved.