English

Geometry of the vapor layer under a Leidenfrost hydrogel sphere

Fluid Dynamics 2026-02-24 v3

Abstract

A floating Leidenfrost droplet exhibits curvature inversion of its underside, due to the balance of vapor pressure and surface tension. Using interferometric imaging, we find different behavior for a levitated hydrogel sphere. Curvature inversion is observed briefly just after deposition, but quickly gives way to a steady state with no inversion. We show the essential role of vaporization on shaping the underbelly of the hydrogel, adding a new component to the interplay between vapor pressure and elastic force

Keywords

Cite

@article{arxiv.2507.04982,
  title  = {Geometry of the vapor layer under a Leidenfrost hydrogel sphere},
  author = {Vicente L. Diaz-Melian and Isaac C. D. Lenton and Jack Binysh and Anton Souslov and Scott R. Waitukaitis},
  journal= {arXiv preprint arXiv:2507.04982},
  year   = {2026}
}

Comments

Figures 2 and 4 were updated, and the text was updated to correspond with the updated figures