Fig. 1. Typical metal implant applications

Fig. 2. Femtosecond laser irradiating metal surface. (a) Electron lattice energy transfer^[65]: (a-1) absorption, (a-2) heating，(a-3) energy transfer, (a-4) ablation; (b) mechanical stripping^[70]; (c) Coulomb explosion^[73]

Fig. 3. TTM-MD method is used to simulate the overall visual image of Al target material splashing irradiated by 100 fs laser pulse^[75] (the atoms are colored according to their potential energy. Blue represents low-energy atoms in the target body, red represents gas-phase atoms. The red dot connected by the red line marks the position of the melting front)

Fig. 4. Finite element simulation of SERS intensity distribution in typical Au nanoparticle structure^[91]

Fig. 5. SERS phenomenon caused by electromagnetic enhancement and chemical enhancement mechanisms. (a) Electromagnetic enhancement mechanism; (b) chemical enhancement mechanism

Fig. 6. Femtosecond laser processing SERS substrate^[106]. (a) Schematic of manufacturing process; (b) SEM image of silver plated substrate; (c) AFM image of silver plated LIPSS surface; (d) absorption spectrum of silver plated LIPSS surface

Fig. 7. Enhancement mechanism of metal surface fluorescence. (a) Plasma oscillation field; (b) fluorescence radiation of SPP regulated molecules

Fig. 8. Microstructure and fluorescence spectra of SEF substrate^[113]. (a) Femtosecond laser induced layered LIPSS; (b) fluorescence spectra under different Cu^2＋ concentrations; (c) linear relationship between spectral intensity and Cu^2＋ concentration

Fig. 9. Microstructure and spectral detection of double reinforced substrates^[118]. (a) Morphology of SERS-SEF substrate; (b) Raman and fluorescence spectra; (c) glucose detection

Fig. 10. Adhesion behavior of cells on base. (a) Protein adsorption; (b) extracellular matrix protein deposition; (c) engineering adhesion

Fig. 11. Cell activity of MC3T3-E1 cultured on Mg-6Gd-0.6Ca alloy with different states and cell adhesion SEM and fluorescence images^[137], where (a-1) represents original surface, (a-2) represents laser remelting surface, (a-3) represents laser remelting＋LIPSS surface, and (a-4) represents laser remelting＋micro groove surface

Fig. 12. Schematic of cell migration process^[139]

Fig. 13. LIPSS regulates cells migration^[142]. (a)(b) Cycle and height of LIPSS; (c)(e) cell migration behavior on original surface, laser remelting surface, laser remelting＋LIPSS surface after 48 h culture; (f)(g) cell fluorescence images of laser remelting surface and laser remelting＋LIPSS surface after 48 h culture

Fig. 14. Proliferation of MC3T3-E1 cultured for one week (significant difference when p < 0.05)^[147]

Fig. 15. Interaction between microstructure and bacteria. (a) Three dimensional diagrams of interaction between bacteria and microstructure^[154], where (a-1) represents bacteria contact the surface of microstructure, (a-2) represents bacteria adsorb to the surface of microstructure, and (a-3) presents rupture of the bacterial cell wall; (b) bacteria adhere to flat surface and microstructure surface^[155], where L and R represent the length and radius of bacteria, respectively, h is the height of nano column, and R_p is the radius of nano column; (c) schematic of bacteria adhering to two adjacent“nano ridges”^[156], where H is the height of“nano ridge”，2R is the bottom width of“nano ridge”， S_A represents contact area between“nano ridge”and bacteria, S_B represents the area of bacteria hanging, r₀ is the distance from the boundary between S_A and S_B to the x-axis, and D is the distance between two adjacent“nano ridges”

Fig. 16. SEM images and schematics of S.aureus and E.coli static and dynamic adhesion on hydrophilic and hydrophobic aluminum substrate surfaces after 24 h culture^[160]

Fig. 17. Adhesion of S.aureus on titanium plate after 48 h culture^[162].(a)(b) Original surface; (c)(d) LIPSS surface; (e)(f) NPs surface

Fig. 18. SEM and CLSM images of P.aeruginosa and S.aureus cultured on micro/nano structure and original surfaces for 18 h, where live bacteria were stained red and EPS was stained green^[164]