Fig. 3: Ultrafast motion of the light-driven micro-rocket in a viscous liquid.

a Theoretical simulation of the microrobots under near-infrared light excitation. The steady distribution of temperature on the micro-rod robot (i), micro-tube robot (ii) and micro-rocket robot (iii). b Movement routes of the micro-rod, micro-tube, and micro-rocket robots in a 50% glycerol solution under near-infrared light actuation. Scale bar: 50 µm. c Instantaneous moving speed of the three microrobots within 1 s. d Average speed of the three microrobots. The micro-tube robot moves at an average speed of 244.6 µm/s, 2.5 times faster than the micro-rod robot, due to the actuation of heat flow from the tube structure. The average speed of the micro-rocket robot reaches 777.4 µm/s, approximately three times that of the micro-tube robot, benefiting from the multiple tubular channels. e Moving distance of the three microrobots. f Average speed of the micro-rocket robot under different power laser actuations (2.8 mm/s under 11.97 µW/µm²)