Droplet impact dynamics on the anisotropic microtextured surface under different wettability

The degree of surface anisotropy, as a significant factor characterizing the complexity of surface morphology, has a notable impact on the morphological evolution and kinetic parameters of droplets in different directions. The present results show that the microtextured surface with stronger surface anisotropy, which is quantified by Str (texture aspect ratio of the surface), has a more drastic effect on droplet deformation and flow path alteration, and the droplet is more likely to fall into the microgroove to form a prompt splash along the transverse direction. In the longitudinal direction, the formation of coronal liquid film can be observed due to the vertical momentum across the microstructure. In addition, the wettability difference caused by anisotropy on the hydrophilic surface has a limited effect on droplet splashing, while the anisotropy of the surface texture distribution has a more significant effect on the droplet splashing behavior. Meanwhile, the synergistic effect of hydrophobicity and anisotropy changes the mass and momentum distribution of the droplet, resulting in decreased contact time of the droplet hitting the solid surfaces. The results of this work are expected to provide valuable insights into controlling droplet spatter in industrial applications.