Topography-Regulated Disorder-to-Order Transition of Condensation Droplets

Condensation of water vapor is a random, transient, and multiscale process prevalent in a variety of natural and industrial processes. Here, we demonstrate that it is possible to transform the disordered distribution of condensate droplets into temporary ordered arrays on chemically homogeneous but physically heterogeneous surfaces, a phenomenon that has not been systematically investigated in a previous study. We show that such a disorder-to-order transition demands an exquisite competition between the length scales of droplets and cavities. In particular, the confinement effect imposed by the patterned cavities should be well controlled to allow the energetically favorable transition.