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Accueil du site > Séminaires > Séminaires 2019 > Séminaire MSC. 4 novembre 2019. Anaïs Gauthier (MIE ESPCI, Paris) : "Levitation above a cryogenic bath : from self-propulsion to capillary orbits ".

Séminaire MSC. 4 novembre 2019. Anaïs Gauthier (MIE ESPCI, Paris) : "Levitation above a cryogenic bath : from self-propulsion to capillary orbits "

Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.


Levitation above a cryogenic bath : from self-propulsion to capillary orbits

Dr. Anaïs Gauthier Institut Chimie, Biologie, Innovation, Equipe Matériaux Innovants pour l’Énergie

Ambient temperature drops deposited on a liquid nitrogen bath can be maintained in the inverse Leidenfrost state, a levitating state that is enabled by a continuous vapor flow produced by the bath. In such freezing conditions, the droplets (which do not evaporate) can levitate for a dozen of minutes. We discuss here how the deformability of the liquid substrate dramatically impacts the particle dynamics. First, we show that a micrometer-sized instability grows within the film sustaining the drop, which causes a partial redirection the vapor flow and generates spontaneous self-propulsion. The drops then behave as active particles, which hover in straight lines above the bath and form a remarkably regular pattern. In addition, the bath deformation at the millimeter scale generates attractive and repulsive interaction between menisci. In this frictionless system, it has striking consequences : first, the particles are repelled at large distance by objects dipped into the bath, which we use as a contactless method to finely control the particles trajectories. In addition, we show that the attraction between identical menisci impacts the motion of approaching droplets which spontaneously orbit around each other – mirroring a miniature celestial system.


Contact : Équipe séminaires / Seminar team - Published on / Publié le 8 octobre


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