Fig. 1. Schematic illustration of femtosecond laser processing system^[31]

Fig. 2. Contact model of a water droplet on the solid surface^[32-34]

Fig. 3. Morphology and wettability of the silicon surface processed by femtosecond laser at different environments. (a)-(d) SF6 environment^[36]; (e)-(h) atmospheric environment^[30]

Fig. 4. Micro/nano-structures formed on various metals surface by femtosecond laser. (a)-(d) Platinum^[38]; (e) brass^[38]; (f) titanium^[38]; (g) stainless steel^[39]; (h) zinc^[41]

Fig. 5. Micro/nano-structures and wettability of various polymers processed by femtosecond laser. (a)-(m) PDMS surface^[42]; (n)-(q) PTFE surface^[48]; (r)-(t) SMP surface^[54]

Fig. 6. Transparent superhydrophobic glass fabricated by femtosecond laser^[58]. (a) Surface morphology; (b)(c) wettability of water droplets on the prepared surface; (d) transparency

Fig. 7. Self-cleaning phenomenon of femtosecond laser-structured superhydrophobic surface^[46]

Fig. 8. Anti-icing property of femtosecond laser-structured superhydrophobic PTFE surface^[59]. (a) Drop the same volume of water on samples; (b) water freezes; (c) result after shaking the samples

Fig. 9. Wettability of femtosecond laser-ablated microhole array aluminum foil surface and oil/water separation process^[60]. (a) Surface wettability; (b) oil/water separation process

Fig. 10. Surface morphology of the silicon surface ablated by laser with different pulse energies and evaporation process of the droplet on the samples surfaces^[61].(a)-(j) Surface morphology; (k) evaporation process

Fig. 11. Transportation process of a water droplet from low-adhesive superhydrophobic surface to high-adhesive superhydrophobic surface^[40]

Fig. 12. Micro/nano-structures morphology on the surface of copper sheet and microfluidic devices^[62]. (a)(c) Morphology and wettability of micro/nano-structures formed on copper sheet surface by laser with different energy densities; (b)(d) surface morphology and wettability of PDMS after template replicating; (e)-(g) microfluidic devices

Fig. 13. Surface morphologies of PDMS and aluminum plate after femtosecond laser ablation and their floating on the water. (a)-(d) PDMS^[63]; (e)-(h) aluminum plate^[64]

Table 1. Crucial parameters for preparing superhydrophobic micro/nano-structures on different materials surfaces by femtosecond laser technology