Séminaire PMMH - Dominic Vella (University of Oxford)

Drops with deformable boundaries : Flat tops, Locomotion and Ageing

A liquid droplet placed on a rigid, planar surface has a captivating simplicity : its surface is a spherical cap and remains in equilibrium. In this talk, I'll show that the addition of a deformable boundary leads to a range of new phenomena : evaporating droplets with an elastic skin may develop flat tops, while droplets placed in a flexible channel invariably push or pull themselves to the end of the channel. Even without a complex rheology or locomotion, reaching equilibrium can happen slowly, with the droplet's contact ageing. I will discuss three specific examples, presenting a combination of theory and experiment for each.