The evaporation of sessile droplets is currently the subject of a great deal of international experimental, numerical and theoretical research activity, but most of the work thus far has, for understandable reasons, focused on the case of a single droplets. However, in practice, droplets rarely occur in isolation and so there is considerable interested in understanding the interactions between multiple evaporating droplets. To this end I shall present recent results on the interactions between two droplets in two dimensions [1] and between multiple thin droplets in three dimensions [2], and, in particular, investigate the effect of these interactions on droplet evolutions and lifetimes, as well as on the famous coffee-ring effect.

[1] Schofield, F.G.H., Wray, A.W., Pritchard, D., Wilson, S.K., The shielding effect extends the lifetimes of two-dimensional sessile droplets, to appear in J. Eng. Maths. (2020)

[2] Wray, A.W., Duffy, B.R., Wilson, S.K., Competitive evaporation of multiple sessile droplets, J. Fluid Mech. 884 A45 (2020)