How Spontaneous Electrowetting and Surface Charge Affect Drop Motion

Physical Review Letters 2026 Open access

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Authors: Chirag Hinduja, Benjamin Leibauer, Rishi Chaurasia, Nikolaus Knorr, Aaron D. Ratschow, Shalini Singh, Hans‐Jürgen Butt, Rüdiger Berger
DOI: 10.1103/9mzt-v9cl
Cited by: 3
References: 85

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 (≤10^{-4}). We find that the drop charge leads to spontaneous electrowetting that decreases the contact angles. 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.

Fields of Study & Subjects

Electrowetting and Microfluidic Technologies Surface Modification and Superhydrophobicity Electrohydrodynamics and Fluid Dynamics

Publication details

Journal / source
Physical Review Letters
Publisher
American Physical Society (APS)
Volume
136
Issue
19
Pages
194001–194001
Publication date
17 March 2026
Language
EN