Wettability-independent droplet transport by Bendotaxis

When a drop is confined in a thin channel with deformable walls, a combination of bending and capillarity causes a pressure gradient that, in turn, results in the spontaneous movement of the liquid. Surprisingly, the direction of this motion, which we refer to as bendotaxis, is always the same, regardless of the wettability of the channel; bendotaxis may therefore be a useful means of transporting droplets on small scales, with various technological applications. This talk will present details of macroscopic experiments and a simple mathematical model used to study this motion, focussing in particular on the time scale associated with the motion, and we discuss the implications of these results.