Synopsis: Stop! Slippery water

Ridges and dips provide control of how a drop of liquid, despite extreme mobility, moves on a very hot surface.

When water drops skitter across a griddle, cooks know that it is hot enough to pour on the pancake batter. These “Leidenfrost” drops are separated from the surface by a cushion of vapor that greatly decreases their resistance to motion.

In a paper in Physical Review Letters, Guillaume Dupeux at CNRS ESPCI in Paris, France, and colleagues tell us how to use textured surfaces to control and even immobilize these drops, stopping them within centimeters instead of meters. On a ridged surface, the drops hit the ridges’ sides, losing kinetic energy on impact. Also, drops often fall partly into the grooves and must overcome the resultant potential energy loss in order to continue moving along the surface. Motion stops abruptly when a drop does not have enough kinetic energy to climb the next ridge.

It is possible that water may experience similar effects on unheated superhydrophobic surfaces, on which drops also make ultramobile pearls that could be controlled or trapped using such textures. – Jane Throwe


Features

More Features »

Announcements

More Announcements »

Subject Areas

Fluid Dynamics

Previous Synopsis

Magnetism

Balance excludes magnetism

Read More »

Next Synopsis

Related Articles

Focus: <i>Video</i>—Fluid Video Contest Winners
Fluid Dynamics

Focus: Video—Fluid Video Contest Winners

Swimming starfish larvae, dripping paint, and swirling gas jets are featured in the APS Division of Fluid Dynamics’ winning videos. Read More »

Synopsis: How to Make Superhydrophobicity Last
Fluid Dynamics

Synopsis: How to Make Superhydrophobicity Last

Researchers find tricks to prolong the typically short-lived water repellency of a superhydrophobic surface. Read More »

Focus: Drops Falling in Clouds Make More Drops
Fluid Dynamics

Focus: Drops Falling in Clouds Make More Drops

Experiments with a simplified version of the atmosphere show that falling drops seed many smaller droplets in their wake. Read More »

More Articles