Layers of Air Under Water

The Aircoating technology is a comprehensively patented process for air-retaining and biological surface coating, which was developed on the model of nature, more precisely the water-repellent floating fern Salvinia Molesta.

This fern has a dense covering of tiny hairs on its leaf surface, which envelops it in a layer of air that cannot escape. If you submerge such a leaf under water, it holds the air for years. In the course of research work at the KIT (Karlsruhe Institute of Technology) to decipher the mechanism that makes it possible to permanently maintain a layer of air under water, artificial surfaces were produced that function according to this principle. In Karlsruhe, a successful sample has now been lying dry under water, surrounded by a stable layer of air, for more than eight years. Since then, the surfaces have been optimised using nanotechnology.

When a ship comes into contact with water, three main effects can be observed, which represent the central problems of shipping: Fouling of the ship’s hull with marine organisms, corrosion of the material by salt water and, above all, frictional resistance during movement. These effects have disastrous economic and ecological consequences: The use of environmentally harmful anti-fouling coatings, furthermore costly maintenance work and above all the high fuel consumption combined with the exorbitant emission of pollutants. This is so enormous that the 50 largest ships emit more toxins than all the cars in the world put together. Aircoating technology promises a remedy through structured and functionalised surfaces that maintain a permanent layer of air under water.

Through continuous development, the Aircoating Technologies process has great potential to be of considerable benefit in other areas of application – beyond shipping.