Wettability of dual-scaled surfaces fabricated by the combination of a conventional silicon wet-etching and a ZnO solution method

Abstract

We introduce effective dual-scaled surfaces using the combination of the conventional silicon wet-etching technique (for microstructures) and a solution method for ZnO nanorod formation (for nanostructures). The microstructures were sloped to facilitate the overall deposition of a ZnO seed layer as well as the growth of nanostructures over the entire surface area. The ZnO nanorods were formed using growth solutions of various pHs. The fabricated dual-scaled surfaces were also coated with hydrophobic self-assembled monolayers (SAMs) and compared with the surfaces without the SAM coating to examine the structural effects on both hydrophilic and hydrophobic regions. A total of 16 different samples were examined and analyzed systematically by comparing the static (i.e. the contact angle) and dynamic (i.e. spreadability and contact angle hysteresis) wettability.