title: Leidenfrost gas ratchets driven by thermal creep.
abstract: We show that thermal creep is at the origin of the recently discovered Leidenfrost ratchet, where liquid droplets float on a vapor layer along a heated sawtooth surface and accelerate to velocities of up to 40  cm/s. As the active element, the asymmetric temperature profile at each ratchet summit rectifies the vapor flow in the boundary layer. This mechanism works at low Reynolds number and provides a novel tool for controlling gas flow at nanostructured surfaces.
authors: Laboratoire Ondes et Matière d'Aquitaine, Université de Bordeaux and CNRS, Talence, France.
authors: Alois
authors: A
authors: Würger