Wetting characteristics of nanoscale water droplet on silicon substrates with effects of surface morphology

The objective of the present study is to explore the wettability of a nanoscale water droplet on silicon (Si) substrates of various surface morphologies by using molecular dynamics simulation. Three diamond lattice planes, i.e. Si(111), Si(100) and Si(110), of the Si substrates with microstructures of square column arrays of various heights and spacing are considered in this study. The wettability of water droplet on such substrates is characterised by contact angle. The distributions of water density and average hydrogen bond number are visualised with the simulation results. In addition, the volume of vapour trapped in the cavities of the surface microstructure is explored. The present results disclose interesting physics about the influences of wall lattice and surface microstructure.