Start-up characteristics of a capsule micro robot applied in intestine

A new capsule robot prototype with function of radial clearance compensation driven by external rotating magnetic field is proposed, based on the established fluid dynamic model, fluid dynamic pressure and swimming speed of the robot with respect to the clearance between the inner pipe wall and the surface of the robot is analyzed. According to the phenomenon that axial propulsion reduces greatly by the increase of radial clearance between inner pipe wall and external surface of the robot, the startup characteristics is investigated. Theoretical analysis and experimental results show that the control on propulsion and swimming speed of the robot is realized by reducing the thickness of dynamic oil membrane through radial clearance self-compensation, and driving performance of the robot is modified greatly.