Many
animals and plants have evolved wonderful hydrophobic abilities
to adapt to the complex climate environment. The microstructure design
of a superhydrophobic surface focuses on bionics and will be restricted
by processing technology. Although certain functions can be achieved,
there is a lack of unified conclusion on the wetting mechanism and
a few quantitative analyses of the continuity of the three-phase contact
line. Therefore, the relationship between the surface microstructure
of the lattice pattern and the critical sliding angle of the water
droplet in the Cassie state was investigated in this paper, and we
proposed a method to quantitatively analyze the continuity of the
three-phase contact line by a dimensionless length f. The results showed that the three-phase contact line was an important
factor to determine the sliding performance of the droplet. The upward
traction force generated by the surface tension through the force
analysis on the three-phase contact line can enhance the sliding ability
of the droplet on the solid surface. There was a good negative linear
correlation between the critical sliding angle and dimensionless length,
which provided a guiding basis for the optimal design of superhydrophobic
surfaces.