From bouncing to floating: the Leidenfrost effect with hydrogel spheres Journal Article

Author(s): Waitukaitis, Scott R; Harth, Kirsten; van Hecke, Martin
Article Title: From bouncing to floating: the Leidenfrost effect with hydrogel spheres
Abstract: The Leidenfrost effect occurs when a liquid or stiff sublimable solid near a hot surface creates enough vapor beneath it to lift itself up and float. In contrast, vaporizable soft solids, e.g., hydrogels, have been shown to exhibit persistent bouncing - the elastic Leidenfrost effect. By carefully lowering hydrogel spheres towards a hot surface, we discover that they are also capable of floating. The bounce-to-float transition is controlled by the approach velocity and temperature, analogously to the "dynamic Leidenfrost effect." For the floating regime, we measure power-law scalings for the gap geometry, which we explain with a model that couples the vaporization rate to the spherical shape. Our results reveal that hydrogels are a promising pathway for controlling floating Leidenfrost objects through shape.
Journal Title: APS Physics, Physical Review Letters
Volume: 121
Issue 4
ISSN: 00319007
Publisher: American Physical Society  
Date Published: 2018-07-25
Start Page: Article number: 048001
DOI: 10.1103/PhysRevLett.121.048001
Notes: We acknowledge funding from the Netherlands Organization for Scientific Research through Grants VICI No. NWO- 680-47-609 (M. v. H. and S. W.) and VENI No. NWO-680- 47-453 (S. W.), and from the German Science Foundation through Grant No. HA8467/1-1 (K. H.).
Open access: no
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