Fig. 1. SEM images of the titanium alloy surface following picosecond laser treatment. (a) Sample obtained when P=25 W, v=500 mm/s, N=5, f=400 kHz; (b) sample obtained when P=25 W, v=1000 mm/s, N=10, f=1000 kHz; (c) sample obtained when P=30 W, v=2000 mm/s, N=10, f=400 kHz

Fig. 2. SPM images of the titanium alloy surface processed by picosecond laser. (a) 3D morphology of sample surface; (b) 2D profile of the groove

Fig. 3. Grooves depth versus scaning speed

Fig. 4. Grooves depth versus scanning times

Fig. 5. SEM image of multiple parallel grooved structure. (a) Spacing is 75 μm; (b) spacing is 150 μm

Fig. 6. Cell culture and actin cytoskeleton