Surface Coating

Young Engineer Develops Fully Water-Repellent Surface

| Editor: Alexander Stark

A junior engineer at TU Dresden has developed a method that makes surfaces completely water- and ice-repellent. This result could be achieved with the use of a laser. In this way, different surfaces can be processed in a short time, creating new industrial opportunities.

Related Companies

Stephan Milles from TU Dresden has managed to treat an aluminum surface with a laser-based process in such a way that water completely drips off.
Stephan Milles from TU Dresden has managed to treat an aluminum surface with a laser-based process in such a way that water completely drips off.
(Source: Tobias Ritz)

In a fraction of a second the drop rolls over the surface - hardly visible to the naked eye. There's no way the drop can get a hold of the structure. Such a surface, on which neither water nor water-like liquids nor ice can adhere, would be useful for many applications. A young scientist at TU Dresden, Stephan Milles, has now developed and scientifically proven this concept. The engineer structured an aluminum plate with a laser in such a way that water droplets and water-like liquids can no longer hold on to it - the surface becomes superhydrophobic. He has now published the scientific proof of this approach in “Scientific Reports”.

This is what the water-repellent effect looks like:

Possible Industrial Applications

Stephan Milles has spent two years developing a surface structure that repels every last drop of water and also greatly delays ice formation. He chose aluminum because this material is industrially important. Milles explained: “When a plane flies through clouds, there's a lot to be gained from delaying the process of ice forming on wings, engines and sensor components, even by a few seconds.”

The rotor blades of wind turbines, huge tanks for liquids in the food industry or measuring instruments are also made of aluminum and react sensitively to ice. The development of the 28-year-old is therefore a real alternative to previous composite materials or surface coatings and offers new industrial opportunities. No additional chemicals or clean room conditions are required for the structuring of the materials.

Lotose Effect: Inspiration from Nature

The drop on a water-repellent surface remains round (left), while the drop on the untreated surface is flat (right). A surface is considered to be particularly water-repellent (superhydrophobic) if the angle between the surface and the droplet is at least 150 degrees.
The drop on a water-repellent surface remains round (left), while the drop on the untreated surface is flat (right). A surface is considered to be particularly water-repellent (superhydrophobic) if the angle between the surface and the droplet is at least 150 degrees.
(Source: Tobias Ritz)

Milles explains the special characteristic of its structure: “Not all water-repellent surfaces are ice-repellent at the same time. My structure can do both.” In order to achieve this effect, the mechanical engineer was the first to apply a complex structure using a specific laser-based process.

He was inspired by nature. The self-cleaning lotus effect, also known from butterfly wings, is based on a micro- and nanostructured surface. “The big challenge was to first find a structure ten times smaller than a human hair and then etching this even more finely,” explains the engineer.

The Aim is to Etch a Square Meter of Aluminum in Just a Few Minutes

The
The aluminum surface treated with a laser is water- and ice-repellent. The distance of the individual structural elements (distance "mountain" to "mountain") is 7 micrometers. By comparison, a human hair has a diameter of 50 to 80 micrometers.
(Source: Milles/TUD)

At the moment Milles is working on being able to process aluminum plates economically and over a large area. For this reason, he decided in favor of the laser interference method. He explains: "Only the laser interference process can process different surfaces in a very short time. Only when a square meter of aluminum can be laser etched in just a few minutes does the process become interesting for industrial applications. Other methods would currently take several hours - and, even then, wouldn't create the required micro- and nanometer-sized structure."

The research work of Milles, who is currently doing his doctorate on this topic under the supervision of the laser expert Prof. Andrés Fabián Lasagni, is funded by the German Research Foundation within the framework of the Reinhart Koselleck project for the "fabrication of large areas of two- and three-level multiscaled textures with multifunctional surface properties using laser-based methods". In June, Milles was honored for this achievement at the International Conference on Nature Inspired Surface Engineering in New Jersey, USA.

This article was first published by konstruktionspraxis

Original by Katharina Juschkat / Translation by Alexander Stark

This article is protected by copyright. You want to use it for your own purpose? Contact us at support.vogel.de (ID: 46180139)