@article{b697bb6fd6ce49c795080c11588b0d61,
title = "Electrostatic charging of jumping droplets",
abstract = "With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two droplets coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy. Here we show that jumping droplets gain a net positive charge that causes them to repel each other mid-flight. We used electric fields to quantify the charge on the droplets and identified the mechanism for the charge accumulation, which is associated with the formation of the electric double layer at the droplet-surface interface. The observation of droplet charge accumulation provides insight into jumping droplet physics as well as processes involving charged liquid droplets. Furthermore, this work is a starting point for more advanced approaches for enhancing jumping droplet surface performance by using external electric fields to control droplet jumping.",
author = "Nenad Miljkovic and Preston, {Daniel J.} and Ryan Enright and Wang, {Evelyn N.}",
note = "Funding Information: We thank Professor Rohit Karnik of the MIT Mechanical Engineering department for fruitful discussions regarding the charging mechanism. We gratefully acknowledge funding support from the MIT S3TEC Center, an Energy Frontier Research Center funded by the Department of Energy, Office of Science, Basic Energy Sciences under Award no. DE-FG02-09ER46577, and the Office of Naval Research (ONR) with Dr Mark Spector as program manager. We also acknowledge the support from the National Science Foundation through the Major Research Instrumentation Grant for Rapid Response Research (MRI-RAPID) for the microgoniometer. We acknowledge support from Semblant and P2i for the hydrophobic layer depositions. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network (NNIN), which is supported by the National Science Foundation under NSF award no. ECS-0335765. CNS is part of Harvard University. D.J.P. acknowledges funding received by the National Science Foundation Graduate Research Fellowship under Grant no. 1122374. Any opinion, findings and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation. R.E. acknowledges funding received from the Irish Research Council for Science, Engineering and Technology, cofunded by Marie Curie Actions under FP7.",
year = "2013",
doi = "10.1038/ncomms3517",
language = "English (US)",
volume = "4",
journal = "Nature Communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
}