Capillary droplets on Leidenfrost micro-ratchets

Abstract

Leidenfrost ratchets are structures with the ability of transporting liquid droplets when heated over the critical Leidenfrost temperature. Once this temperature is reached, the droplet levitates over the surface and moves in the direction marked by the slope of the ratchet at terminal velocities around 10 cm/s. Here we provide new experiments with micron-sized ratchets, which have been produced with picosecond pulse laser ablation. In the following work, we use a simple method to measure the thrust driving droplets of capillary size over the micro-ratchets. The mechanism responsible for the force acting on the drop on superheated ratchets has been recently under debate. We extend the recently proposed 'viscous mechanism' proposed by Dupeaux et al. [Europhys. Lett., 96, 58001 (2011)] to capillary droplets and find good agreement with our measurements.

Accepted for publication in Physics of Fluids journal, http://pof.aip.org/

References in corpus (6)

• The Geometry of the Vapor Layer Under a Leidenfrost Drop
• Entropic Splitter for Particle Separation
• Maximum size of drops levitated by an air cushion
• Leidenfrost Gas Ratchets Driven by Thermal Creep
• Propulsion Mechanisms for Leidenfrost Solids on Ratchets
• Thermally-driven flows between a Leidenfrost solid and a ratchet surface

Cited by in corpus (5)

• Controlling heat transport and flow structures in thermal turbulence using ratchet surfaces
• Self-propulsion of inverse Leidenfrost drops on a cryogenic bath
• Lattice Boltzmann modeling of self-propelled Leidenfrost droplets on ratchet surfaces
• Creation of Material Functions by Nanostructuring
• Small Leidenfrost droplet dynamics