Fig. 1. Schematic of femtosecond laser processing system

Fig. 2. Surface morphologies of silicone rubber before and after femtosecond laser treatment. (a) Before treatment; (b) after treatment

Fig. 3. Bar diagram of contact angle and rolling-off angle of silicone rubber surface

Fig. 4. Schematic of aging test

Fig. 5. Contact angles of silicone rubber surface under different accelerated aging time

Fig. 6. Slope rolling states of silicone rubber surface after aging for 700 h. (a) Original surface; (b) silicone rubber surface after 5.0 J ·cm^－2 laser processing

Fig. 7. Roughness and root mean square slope of aged silicone rubber surface. (a) Roughness; (b) root mean square slope

Fig. 8. Microstructures on silicone rubber surfaces etched with different laser energy densities before and after aging for 700 h. (a) Original surface; (b) 2.5 J ·cm^－2; (c) 5.0 J ·cm^－2; (d) 10.0 J ·cm^－2

Fig. 9. ATR-FTIRs of original silicone rubber and sample surface processed by laser with 5.0 J ·cm^－2

Fig. 10. ATR-FTIRs of samples processed by lasers with different energy densities after aging for 700 h

Fig. 11. Contact angle and rolling-off angle of aged sample processed by laser with different energy densities after heat treatment. (a) Contact angle; (b) rolling-off angle

Fig. 12. Roughness and root mean square slope of aged sample surface after laser processing with different laser energy densities after heat treatment. (a) Roughness; (b) root mean square slope

Fig. 13. ATR-FTIR of aged samples surface processed by laser with 5 J ·cm^－2 after heat treatment

Fig. 14. Microstructures on aged silicone rubber surfaces irradiated by laser with 5.0 J ·cm^－2 after heat treatment. (a) 0; (b) 20 h; (c) 40 h