Fig. 5: Untethered multimode magnetic turbine robot.

a Photograph of continuously printing the turbine robot into customized sizes (typically ~12.5 mm diameter and ~5.4 mm height). b The simulation analysis of a typical flow field around the rotating swimming turbine robot in an underwater pipe with a diameter of 20 mm. The trapping vortex behind the robot is marked in gray color, where the vector direction of the Y-axis component velocity is opposed to the Y direction. v, swimming speed; f, rotating frequency. c The relative velocity component in the Y direction of trapped objects to the robot under varying swimming speeds and rotating frequencies. d The removal process of sticky blockages in an underwater straight tube by using the turbine robot to trap floating obstacles and avoid blockage migration. Typical processes include: Swimming to the target location, rotating sweeping, flipping (mode switching), vortex trapping, and dragging for removal. The propulsion and rotation directions of the robot are marked in white and brown, respectively. e The multimode turbine robot transports a capsular-like cargo through a Y-shape tube by steering its rotational axis. The angle between the front and rear paths is about 125.6°. Scale bars, 5 mm.