A hydrophobicity study on wavy and orthogonal textured surfaces

A numerical study was carried out to investigate the wetting characteristics of both an orthogonal type surface and a wavy type surface at the nano-scale by means of the molecular dynamics simulation method. In this study, the contact angles of a droplet on orthogonal type surfaces and on wavy type surfaces were used to compare the wetting characteristics of orthogonal stripe-patterned surfaces with those of wavy-patterned surfaces. The water droplet is less affected by the various orthogonal type and wavy type surfaces when the primary texture height of the structure and surface energy are relatively low. However, as the primary texture height of the structure and surface energy increase, the results of a one directional textured pattern is different from those of the dual direction textured pattern. In the cases of the orthogonal stripe-patterned surfaces and the wavy-patterned surfaces having a one directional pattern, the geometric difference indicates that the wavy type surface have a contact angle as much 85° higher than the orthogonal type surface. However, when comparing the orthogonal and wavy dual direction patterned surfaces, there is never more than 17° difference.