Bionic Coating for Fuel-Efficient Ships

Wednesday, May 05 2010

The water fern salvinia molesta is extremely hydrophobic, surrounding itself by a flimsy skirt of air that prevents the plant from coming into contact with liquid. This inconspicuous plant could allow ships to have a 10 percent decrease in fuel consumption.

Researchers at the University of Bonn, Rostock, and Karlsruhe in Germany have now discovered how the fern does this. Their results can possibly be used for the construction of new kinds of hulls which glide through the water in an envelope of air. Such kinds of ships would get by with significantly less fuel due to decreased friction.

Materials researchers call the water fern's behavior 'superhydrophobic'. This property is of interest for many applications such as rapidly drying swimsuits or simply for fuel-efficient ships. Meanwhile, it is possible to construct superhydrophobic surfaces modeled on nature. However, these replicas have a disadvantage: the layer that forms on them is too unstable. In moving water it disappears after several hours at the latest.

The researchers from Bonn, Rostock, and Karlsruhe have now deciphered the trick the water fern uses to pin down its airy skirt. It has been known for some years now that on the surface of its leaves there are tiny whisk-like hairs. These are hydrophobic and keep water in the surroundings at a distance.