Applied physics

Jumping droplets repel each other

Journal name:
Nature
Volume:
502,
Page:
8
Date published:
DOI:
doi:10.1038/502008c
Published online

Water droplets that form on strongly repellent surfaces often coalesce and leap off. When they do, they carry an electric charge that can be used to control them.

NENAD MILJKOVIC AND DANIEL J. PRESTON/MIT

Evelyn Wang at the Massachusetts Institute of Technology in Cambridge and her colleagues observed that jumping droplets sometimes repel each other in the air (pictured). To learn why, they studied droplets coalescing on a superhydrophobic copper oxide nanostructure, and found that the droplets sometimes gain a small positive charge as they merge and leap into the air.

The authors suggest that this electrostatic effect could be exploited to remove or manipulate the droplets, and so produce surfaces that can be easily cleaned or de-iced.

Nature Commun. 4, 2517 (2013)

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