Capillary droplets on Leidenfrost micro-ratchets

@article{Marin2012CapillaryDO,
  title={Capillary droplets on Leidenfrost micro-ratchets},
  author={Alvaro Marin and Daniel Arnaldo del Cerro and G. R. B. E. Romer and B. Pathiraj and A. J. Huis in 't Veld and Detlef Lohse},
  journal={Physics of Fluids},
  year={2012},
  volume={24},
  pages={1-10}
}
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… Expand

Figures from this paper

Rectification of Mobile Leidenfrost Droplets by Planar Ratchets.
TLDR
The design of planar ratchets enriches the fundamental understanding of how the surface topography is translated into dynamic and collective droplet transport behaviors, and also imparts higher applicability in microelectromechanical system based fluidic devices. Expand
Lattice Boltzmann modeling of self-propelled Leidenfrost droplets on ratchet surfaces.
TLDR
It is numerically shown that the motion of self-propelled Leidenfrost droplets on ratchet surfaces is owing to the asymmetry of the ratchets and the vapor flows beneath the droplets, which agrees with the direction of droplet motion in experiments. Expand
Fast & Scalded: Capillary Leidenfrost Droplets in micro-Ratches
In this Fluid Dynamics Videos submitted to the 31st Gallery of Fluid Motion, (find a different version here this http URL) we illustrate the special dynamics of capillary self-propelled LeidenfrostExpand
Reversible self-propelled Leidenfrost droplets on ratchet surfaces
We investigate the self-propelled motion of the Leidenfrost droplets on hot surfaces with ratchet like topology. It is found that on hot ratchet surfaces with the certain geometry parameters, theExpand
Asymmetric wettability of nanostructures directs leidenfrost droplets.
TLDR
The fabrication and characterization of tilted nanopillar arrays (TNPAs) that exhibit directional Leidenfrost water droplets under dynamic conditions, namely on impact with Weber numbers ≥40 at T ≥ 325 °C are reported. Expand
Propulsion on a superhydrophobic ratchet
TLDR
It is shown that coating ratchets with super-hydrophobic microtextures extends quick self-propulsion down to a substrate temperature of 100°C, which exploits the persistence of Leidenfrost state with such coatings. Expand
Self-propelled rotation of paper-based Leidenfrost rotor
When a liquid droplet is placed on a sufficiently hot surface, it will be levitated by the vapor cushion between the droplet and the hot surface due to the Leidenfrost effect. Such Leidenfrost-basedExpand
Leidenfrost droplet trampolining
TLDR
It is found that the continuously draining vapor cushion initiates and fuels Leidenfrost trampolining by inducing ripples on the droplet bottom surface, which translate into pressure oscillations and induce self-sustained periodic vertical droplet bouncing over a broad range of experimental conditions. Expand
Self-propelling Leidenfrost droplets on a variable topography surface
Leidenfrost water droplets can self-propel on heated surfaces with ratcheted topography, a very useful characteristic for systems with excess heat where fluid flow without moving parts is desirable.Expand
Self-propelled Leidenfrost drops on a thermal gradient: A theoretical study
We theoretically investigate the behavior of Leidenfrost drops on a flat substrate submitted to a horizontal thermal gradient and highlight that they are able to self-propel in a preferentialExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 20 REFERENCES
Propulsion of droplets on micro- and sub-micron ratchet surfaces in the Leidenfrost temperature regime
Spatially periodic systems with localized asymmetric surface structures (ratchets) can induce directed transport of matter (liquid/particles) in the absence of net force. Here, we show thatExpand
A ratchet trap for Leidenfrost drops
Abstract The Leidenfrost effect occurs when a drop of liquid (or a sublimating solid) is levitated above a sufficiently hot surface through the action of an insulating vapour layer flowing from itsExpand
Viscous mechanism for Leidenfrost propulsion on a ratchet
An evaporating drop placed on a ratchet self-propels, as discovered by Linke et al. in 2006. Sublimating platelets do the same, and we discuss here a possible viscous mechanism for these motions. WeExpand
Self-propelled Leidenfrost droplets.
TLDR
It is reported that liquids perform self-propelled motion when they are placed in contact with hot surfaces with asymmetric (ratchetlike) topology and proposed that liquid motion is driven by a viscous force exerted by vapor flow between the solid and the liquid. Expand
Leidenfrost gas ratchets driven by thermal creep.
  • A. Würger
  • Materials Science, Medicine
  • Physical review letters
  • 2011
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 velocitiesExpand
Leidenfrost point reduction on micropatterned metallic surfaces.
TLDR
A micropatterned surface is presented here that significantly reduces the Leidenfrost point, and the temperature increase, relative to the boiling point, required to reach the LFP is 70% lower than that on the flat surface. Expand
Thermally driven flows between a Leidenfrost solid and a ratchet surface.
TLDR
It is found that thermally driven flows make an insignificant contribution to the thrust of Leidenfrost solids on ratchet surfaces, which is dominated by the pressure-driven flow due to the sublimating solid. Expand
Trapping leidenfrost drops with crenelations.
TLDR
This work shows how crenelated surfaces can be used to increase the friction of Leidenfrost drops by a factor on the order of 100, making them decelerate and be trapped on centimetric distances instead of the usual metric ones. Expand
Leidenfrost drops
A Leidenfrost drop forms when a volatile liquid is brought in contact with a very hot solid. Then, a vapor film comes in between the solid and the drop, giving to the latter the appearance of aExpand
Geometry of the vapor layer under a leidenfrost drop.
TLDR
Using laser-light interference coupled to high-speed imaging, the radius, curvature, and height of the vapor pocket, as well as nonaxisymmetric fluctuations of the interface for water drops at different temperatures, are measured. Expand
...
1
2
...