# Anti-Adhesion Superhydrophobic High-Frequency Electrotome
## 3 Results and Discussion  
We fabricated SH-HFES by laser processing and stearic acid modification. In this study, we first explored the influence of laser scanning parameters on the surface wettability and morphology of HFEs. Since the adjustment of the laser parameters changes the surface morphology, if the morphology of the patterned microstructure and the surface structure change at the same time, it will complicate the study of the effect of the patterned microstructure on the hydrophobicity and anti-adhesive properties alone. Therefore, we first determined the optimal processing parameters and then used these parameters to process different patterned microstructures to ensure the consistency of the structure morphology. As shown in Figure 3a, the superhydrophobicity of the sample reaches a steady state when the laser power is 9 W, the contact angle is 159\({}^{\circ}\), and the surface roughness \(Sa\) is 1.13 \(\upmu\)m. Further investigating the influence of scanning speed, as shown in Figure 3b, we found that the sample maintains a higher superhydrophobicity (contact angle of 161\({}^{\circ}\)) when the scanning speed is 500 mm/s. The surface roughness \(Sa\) decreased to 1.08 \(\upmu\)m, which exhibited a lower surface roughness. To achieve better superhydrophobicity and uniform morphology, we also explored the influence of line spacing on wettability and morphology. As shown in Figure 3d, when the line spacing is 10 \(\upmu\)m, the contact angle is the highest, reaching 162\({}^{\circ}\), while at the same time, the laser-etched morphology is the most homogeneous at the smallest laser line spacing, and the surface roughness \(Sa\) decreases to 1.0 \(\upmu\)m. In addition, the number of scans does not have much effect on the surface wettability and morphology, as shown in Figure 3c; with the increase in the number of scans, the superhydrophobicity tends to be stabilized, and the surface roughness only slightly increases. The water contact angle and Zygo image of the untreated HFE surface are shown in Figures S1 and S2. Detailed data can be found in Tables S1-S4. Therefore, we chose the laser processing parameters of 9 W laser power, 500 mm/s scanning speed, 10 \(\upmu\)m line spacing, and one repeat scan. After processing the patterned microstructures with optimal parameters, as shown in Figure 3e, we observed that SAP1, SAP2, and SAP3 could be superhydrophobic. The combination of surface micromorphology and low surface energy is a key factor in conferring superhydrophobicity and excellent anti-adhesion properties to HFE surfaces [33; 34; 35; 36]. The surface prepared by laser treatment was shown to be homogeneous and consisted of many papillary microscale structures, which favored the surface, as shown in Figure 4a, by scanning electron microscopy images. With the Zygo image, as shown in Figure 4b, we visualized the height distribution of the surface design pattern. This image clearly presented the three-dimensional characteristics of the microstructure formed by laser processing. Figure 2: (a) Tissue cutting displacement platform. (b) Schematic diagram of cut tissue. The chemical groups on the surface of the ordinary HFE and SH-HFEs were analyzed using FTIR spectroscopy. As shown in Figure 5a, in the high-frequency region, the absorption peaks of the SH-HFE are located near 2913 cm\({}^{-1}\) and 2846 cm\({}^{-1}\), which belong to the asymmetric and symmetric stretching vibrations of C-H, respectively. In the low-frequency region, an absorption peak of 1697 cm\({}^{-1}\) appears on the surface of the SH-HFEs compared with that of the ordinary HFE, which belong to the C=O stretching vibrations in the carboxyl group. Considering the chemical modifications, the appearance of the C  
Figure 3: Influence of different (**a**) laser powers, (**b**) scanning speeds, (**c**) processing times, and (**d**) line spacing on contact angle and surface roughness. (**e**) Influence of different patterned microstructures on surface wettability. The optimal parameters are circled in Figures (**a–d**).