Viscous mechanism for Leidenfrost propulsion on a ratchet

ORAL

Abstract

An evaporating drop placed on a ratchet shaped substrate self-propels, as discovered by Linke et al. in 2006. Sublimating platelets of dry ice do the same, and we discuss a possible viscous mechanism for these motions. We report that the flow of vapor below the levitating material is rectified by the asymmetric teeth of the ratchet, in the direction of descending slopes along each tooth. As a consequence, the resulting viscous stress can entrain the material in the same direction, and we discuss the resulting self-propelling force.

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Authors

  • Guillaume Dupeux

    Physique et Mecanique des Milieux Heterogenes, CNRS, ESPCI, Paris France \& Ladhyx, CNRS, Ecole Polytechnique, Palaiseau, France

  • Christophe Clanet

    Physique et m\'ecanique des milieux heterogenes, CNRS, ESPCI, Paris, France \& Ladhyx, CNRS, Ecole Polytechnique, Palaiseau, France, Physique et Mecanique des Milieux Heterogenes, CNRS, ESPCI, Paris France \& Ladhyx, CNRS, Ecole Polytechnique, Palaiseau, France

  • Steffan Hardt

    Center of Smart Interfaces, Technische Universitat Darmstadt, Germany, Institute of Nano- \& Microfluidics, Center of Smart Interfaces, TU Darmstadt, Center of Smart Interfaces, TU Darmstadt, Technical University of Darmstadt

  • David Quere

    Physique et m\'ecanique des milieux heterogenes, CNRS, ESPCI, Paris, France \& Ladhyx, CNRS, Ecole Polytechnique, Palaiseau, France, Physique et Mecanique des Milieux Heterogenes, CNRS, ESPCI, Paris France \& Ladhyx, CNRS, Ecole Polytechnique, Palaiseau, France