Drops hop from hydrophilic surfaces

The impact of liquid droplets on solid surfaces is ubiquitous in many natural and industrial settings. It is now well known that drops can bounce on super-hydrophobic surfaces such as the leaf of a lotus plant or a patterned engineered surface, coated to repel water. Furthermore, it is commonly thought that when impacting hydrophilic substrates, for instance a glass window, drops will splash or spread but never bounce. Here, this assumption is shown to be incorrect - drops do in fact bounce on smooth and defect-free hydrophilic substrates such as very clean glass, silicon wafers, or the surface of cleaved mica.