the pitcher plant and

the aquaplaning ants

The Nepenthes is a carnivorous pitcher plant found in various parts of the tropics, where it is often wet and raining. After each rain, a thin water film is trapped at the rim of the pitcher plant, resulting in a highly slippery surface; an ant which is unfortunate enough to find itself on the rim will invariably slip and aquaplane into the inside of the pitcher: a watery grave filled with digestive juices from the plant (See video above).

Based on a similar principle—a solid surface infused with a thin liquid film (lubricant)—scientists have developed surfaces which can repel a wide-range of 'sticky' liquids, from blood to crude oil.

See here and here.

In a recent publication, I explained the origin of this extreme liquid-repellency. A thin lubricant film can be stabilized in between the droplet and the solid substrate, and as the droplet moves, it is essentially levitating over another liquid, with no contact with the solid.

The presence of this intercalated film also explains the ability of such surfaces to repel ice, bacteria, and marine organisms.

© 2019 by Dan Daniel