Abstract: A new kind of micro robot is proposed. This kind of the micro robot can move in micro-tubes full of fluids. When it moves in micro-tubes full of fluids, the hydrodynamic fluid film will form. The film can prevent the direct contact between it and the micro-tubes. The locomotion speed and hydrodynamic fluid film thickness formed when it moves in micro-tubes full of fluids are calculated according to the hydrodynamic lubrication theory. The results indicate that the micro-robot can be suspended to move quickly in micro-tubes full of fluids. The above results are confirmed by the experiments. This kind of the micro robot especially suits to move in endocoeles or blood vessel.

Key words: Micro-robot, Micro-tube, Spiral ribbed impeller