Rapid Droplet Detachment via Pancake Bouncing

Synopsis

Minimizing the contact time of droplets has many important applications such as anit-icing and self-cleaning. Liu et al. were able to show that water dropped on a superhydrophobic surface made of submillimeter-scale posts coated in nanotextures deforms into a pancake shape and leaves the surface while still in this shape. This is different to an convectional bounce where the drop would regain a spherical shape before leaving the surface. When measuring the total contact time of the water, the pancake bounces had a fourfold reduction in contact time when comparted to a convectional bounce. Finally, by tapering the posts coated in nanotextures Liu et al. found that posts begin to behave like harmonic springs and the pancake bouncing was exhibited for a wide range of impact velocities.