Anisotropic Ice Adhesion of Micro-Nano-Structured Metal Surface by a Femtosecond Laser

Abstract

The icephobic materials induced using micro-nano-structured surfaces have aroused great attention for promising applications. Previously, the characterization of ice adhesion of icephobic materials by shear force is usually performed without direction discrimination along the surface whatever the surface is anisotropic or not. In this work, we studied the direction-dependent ice adhesion strength on groove-shaped micro-nano-structured aluminum alloy surfaces formed using a femtosecond laser. It is found that the ice adhesion strength on the surfaces exhibits anisotropy, which corresponds to a smaller ice adhesion strength in the direction parallel to the groove than that orthogonal to the groove. Furthermore, it is found that the ice adhesion strength decreases with the increase in groove width in the orthogonal direction, while it does not change much in the parallel direction. The anisotropic ice adhesion strength is attributed to the change of wettability and morphology in the two directions. The findings in this work suggest that anisotropic ice adhesion should be fully considered when designing an icephobic micro-nano-structured metal structure, which is of great significance to the characterization and application of icephobic materials.

Directional Drop Rebound on Adhesive-Gradient Micro–Nanostructured Surfaces Formed by a Femtosecond Laser

“…Correspondingly, the contact state model changes from the Cassie model to the Wenzel model, resulting in an increase in adhesion . The reason for the anisotropic adhesive properties exhibited by the surface of the grooved structure in different directions is that the surface with the structure will produce extra wetting resistance in the direction perpendicular to the groove . Since there are more changes in the transverse rolling angle (as shown in Figure d), there are more abundant choices for the selection of structural parameters in subsequent experiments.…”

“…20 The reason for the anisotropic adhesive properties exhibited by the surface of the grooved structure in different directions is that the surface with the structure will produce extra wetting resistance in the direction perpendicular to the groove. 13 Since there are more changes in the transverse rolling angle (as shown in Figure 1d), there are more abundant choices for the selection of structural parameters in subsequent experiments. Therefore, in the follow-up experimental data analysis, the transverse rolling angle data is selected.…”

“…In addition, due to the existence of a one-dimensional groove structure on the surface of the sample, the groove structure is a surface with anisotropic wetting characteristics. The reason for the wetting characteristics anisotropy is the change in the length and continuity of the three-phase contact line in the inclined direction at different inclination angles . Therefore, the wetting characteristics of the sample surface were characterized from two perspectives: parallel to the groove direction (lateral direction) and perpendicular to the groove direction (longitudinal direction) (as shown in Figure c).…”

“…Femtosecond laser micro–nano-processing technology has been proven to be an excellent surface micro–nanostructure processing method for almost all materials. Through the control of the micro–nanostructure, the prepared micro–nanostructured surface exhibits rich wetting properties. − Therefore, femtosecond laser micro–nano-fabrication technology is an excellent candidate for preparing surfaces with differentiated adhesion and for conducting research on the rebound control of impact droplets. Compared with the traditional surface micro–nanostructure preparation method, femtosecond laser technology has significant advantages and excellent engineering application prospects. , …”

Fabrication of Superhydrophobic Gully-Structured Surfaces by Femtosecond Laser and Imprinting for High-Efficiency Self-Cleaning Rain Collection

“…Typical ways to collect rain use a roof coated with lead paint or fittings, which causes potential pollution by toxic chemicals. , More recently, femtosecond (fs) laser fabrication has been used as a new manufacturing method for developing functional surfaces in water collection applications . Compared to conventional machining processes, femtosecond laser fabrication is more precise processing for multifunctional surfaces, including micro-nanoscale structures without mechanical stress, and multiple materials such as semiconductors, metal, plastic, glass, ceramics, and graphene. − At the same time, femtosecond laser fabrication is also uncomplicated processing and is available for industry . Moreover, the femtosecond laser is used for fabricating mircro-nanoscale structures with the desired photonic, thermal, and superhydrophilic or superhydrophobic properties. − …”