Fig. 1. Experimental device. (a) Schematic of laser-induced liquid micro-jet system; (b) schematic of micro-jet device and parameters used in the study

Fig. 2. Micro-jet mechanism and cavitation bubble pulsation process. (a) Basic working principle of laser-induced liquid micro-jet system; (b) pulsation process of cavitation bubble generated by 10.6 μm CO₂ laser focused in water

Fig. 3. Dynamic process of four types of jet injections [shooting speed: 18540 frame/s; image interval: 1 frame (except otherwise indicated)]. (a) Columnar jet (image interval: 10 frame); (b) mushroom-shaped jet; (c) acicular jet; (d) turbulent state jet

Fig. 4. Dynamic characteristics of jets and jet diameter as a function of time. (a) Dynamic characteristics of four types of jets when P= 25 W and D=3 mm; (b) variation of laser-induced jet diameter (measured at nozzle) with time when D=3,5,7 mm

Fig. 5. Factors affecting jet velocity. (a) Jet velocity of pure water at different laser powers (D=3 mm); (b) jet velocity at different D values (P=20 W)

Fig. 6. Effect of laser acting on agarose gel model. (a) Plan and three-dimensional depth maps of pit (S<2 mm); (b) plan and three-dimensional depth maps of pit (S≥2 mm); (c) influence of distance between agarose gel model and nozzle on pit depth; (d) schematic of tumor removal by laser-induced micro-jet; (e) radius and depth of pits produced on different biological tissue models