## 3 Results and Discussion  
The wetting properties of the surfaces were influenced both by their chemical composition and by their morphology--i.e., corrugation [25; 26]. The influence of the different chemical composition is represented by different materials of the topmost layers, while the influence of the morphology is caused by the interaction with the laser. The role of the more complex multilayer structure is represented by using 8\(\times\)(Zr/Cr/Ti) samples. Exposing the samples to the fs laser beam generated LIPSS on the surfaces, shown in Figure 1. LIPSS on the surface of 15\(\times\)(Ti/Zr) on Si are shown for two magnifications in Figure 1a,b. LIPSS on the 8\(\times\)(Zr/Cr/Ti) are presented in Figure 1c,d, and also for two different magnifications. In addition to wavy-patterned LIPSS, the occurrence of nanoparticles with dimensions less than the periods of LIPSS, is also noticeable. Since the ablation threshold for the multilayer components is lower than the applied fluence, the ablation of the multilayer samples was expected [27]. The experiment with similar conditions (beam, environment, material), created similar ablative LIPSS, while the remaining material in the laser-affected area retained the layered structure (alternating Ti and Zr layers) [28]. Due to the similarity in both conditions and of the outcomes (LIPSS) between the two experiments, it is possible to assume that in the presented experiment the material also retained layered structure in laser affected zones and there were no drastic changes in Ti, Zr, Si and O components among the three zones--the center of, the periphery of, and away from the laser-affected zone. Figure 1: SEM micrographs of LIPSS on the surface of the: (**a**) 15\(\times\)(Ti/Zr) on Si, magnification 5000\(\times\); (**b**) 15\(\times\)(Ti/Zr) on Si, magnification 30,000\(\times\); (**c**) 8\(\times\)(Zr/Cr/Ti) on Si, magnification 5000\(\times\); (**d**) 8\(\times\)(Zr/Cr/Ti) on Si, magnification 30,000\(\times\). SEM results (Figure 1) reveal that there is a periodicity in the pattern, but the 2 DFFT processing of LIPSS micrograph from Figure 1a presented in Figure 2 provides better insight. The appearance of the maxima (inset in Figure 2) shows that the structures are periodic. A clear distinction in the maxima indicates that LIPSS are highly regular, due to the multi-layer structure. By the convenient combination of the materials, the existence of the underneath layer produces a steep change in the layers' temperatures and enables the transfer of thermal energy through the interface and away from the interaction zone [11]. The interaction of fs beam with multilayer thin film materials induces the intermixing of initially separated layers, which could be attributed to the alloying between the components [29]. Due to no drastic changes in the components, not much of the oxides were produced, suggesting that their contribution to the CA value was not significant. The contact angle of a surface processed by laser beam evolves after the processing. It was shown for some alloys that CA increases to the equilibrium level with a higher rate for lower implemented laser fluence: for alloys containing Ti and fluence of 0.78 J/cm\({}^{2}\), it takes a couple of days to be close enough to the equilibrium [16]. The images of water droplets, placed on the surfaces both unexposed and exposed to fs beams, are presented in Figure 3. For 15\(\times\)(Ti/Zr), the droplets are shown in Figure 3a (on unexposed surface) and Figure 3b (on exposed surface). Different shapes indicate the influence of the laser-induced change of the surface, which is twofold: both in the morphology and in the chemical composition. Similar holds for the droplets on the 15\(\times\)(Zr/Ti) unexposed (Figure 3c) and exposed (Figure 3d) surfaces, as well as on the 8\(\times\)(Zr/Cr/Ti) unexposed (Figure 3e) and exposed (Figure 3f) surfaces.