How Spontaneous Electrowetting and Surface Charge affect Drop Motion
Fluid Dynamics
2026-03-20 v1 Soft Condensed Matter
Abstract
Water drops sliding on hydrophobic surfaces spontaneously separate charges at their rear. It is unclear how this charge separation affects the contact angles of a sliding drop. We slide grounded and insulated drops on hydrophobic surfaces at low capillary numbers (\leq 10^{-4}). We find that drop charge leads to spontaneous electrowetting, which decreases the contact angles. Additionally, the deposited charges lead to a surface charge effect and decrease the contact angle. Both phenomena compensate each other at the receding contact line, resulting in an insignificant change in the receding contact angle of a sliding drop.
Cite
@article{arxiv.2602.03362,
title = {How Spontaneous Electrowetting and Surface Charge affect Drop Motion},
author = {Chirag Hinduja and Benjamin Leibauer and Rishi Chaurasia and Nikolaus Knorr and Aaron D. Ratschow and Shalini Singh and Hans-Jürgen Butt and Rüdiger Berger},
journal= {arXiv preprint arXiv:2602.03362},
year = {2026}
}
Comments
Under review as a full research article at Physical Review Letters. Contains 4 figures