Jump to main content
Jump to site search

Issue 48, 2016
Previous Article Next Article

Electric field makes Leidenfrost droplets take a leap

Author affiliations

Abstract

Leidenfrost droplets, i.e. droplets whose mobility is ensured by a thin vapor film between the droplet and a hot plate, are exposed to an external electric field. We find that in a strong vertical electric field the droplet can start to bounce progressively higher, defying gravitational attraction. From the droplet's trajectory we infer the temporal evolution of the amount of charge on the droplet. This reveals that the charge starts high and then decreases in steps as the droplet slowly evaporates. After each discharge event the charge is in a fixed proportion to the droplet's surface area. We show that this behavior can be accurately modeled by treating the droplet as a conducting sphere that occasionally makes electrical contact with the hot plate, at intervals dictated by an electro-capillary instability in the vapor film. An analysis of the kinetic and potential energies of the bouncing droplet reveals that, while the overall motion is damped, the droplet occasionally experiences a sudden boost, keeping its energy close to the value for which the free fall trajectory and droplet oscillation are in sync. This helps the droplet to escape from the hot surface when finally the electrical surface forces overtake gravity.

Graphical abstract: Electric field makes Leidenfrost droplets take a leap

Back to tab navigation

Publication details

The article was received on 30 Jun 2016, accepted on 30 Oct 2016 and first published on 02 Nov 2016


Article type: Paper
DOI: 10.1039/C6SM01506A
Citation: Soft Matter, 2016,12, 9622-9632
  •   Request permissions

    Electric field makes Leidenfrost droplets take a leap

    S. Wildeman and C. Sun, Soft Matter, 2016, 12, 9622
    DOI: 10.1039/C6SM01506A

Search articles by author

Spotlight

Advertisements