Wettability-independent droplet transport by Bendotaxis

Journal article

We demonstrate “bendotaxis,” a novel mechanism for droplet self-transport at small scales. A combination of bending and capillarity in a thin channel causes a pressure gradient that, in turn, results in the spontaneous movement of a liquid droplet. Surprisingly, the direction of this motion is always the same, regardless of the wettability of the channel. We use a combination of experiments at a macroscopic scale and a simple mathematical model to study this motion, focusing in particular on the timescale associated with the motion. We suggest that bendotaxis may be a useful means of transporting droplets in technological applications, e.g., in developing self-cleaning surfaces, and discuss the implications of our results for such applications.

Authors: Bradley, A; Box, F; Hewitt, I; Vella, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Letters
• Volume: 122
• Issue: 7
• Article number: 074503
• Publication date: 2019-02-22
• Acceptance date: 2019-01-22
• DOI: 10.1103/PhysRevLett.122.074503
• EISSN: 1079-7114
• ISSN: 0031-9007