Coupling the Leidenfrost Effect and Elastic Deformations to Power Sustained Bouncing

Autor: Waitukaitis, Scott R., Zuiderwijk, Antal, Souslov, Anton, Coulais, Corentin, van Hecke, Martin
Rok vydání: 2017
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1038/nphys4194
Popis: The Leidenfrost effect occurs when an object near a hot surface vaporizes rapidly enough to lift itself up and hover. Although well-understood for liquids and stiff sublimable solids, nothing is known about the effect with materials whose stiffness lies between these extremes. Here we introduce a new phenomenon that occurs with vaporizable soft solids: the elastic Leidenfrost effect. By dropping hydrogel spheres onto hot surfaces we find that, rather than hovering, they energetically bounce several times their diameter for minutes at a time. With high-speed video during a single impact, we uncover high-frequency microscopic gap dynamics at the sphere-substrate interface. We show how these otherwise-hidden agitations constitute work cycles that harvest mechanical energy from the vapour and sustain the bouncing. Our findings unleash a powerful and widely applicable strategy for injecting mechanical energy into soft materials, with relevance to fields ranging from soft robotics and metamaterials to microfluidics and active matter.
Databáze: arXiv