Micro- and Nanostructuring

Surface structuring for customization of the wetting behavior and adhesion properties

Water droplet on structured and hydrophobic coated ABS.
© Fraunhofer IFAM
Water droplet on structured and hydrophobic coated ABS.
EFTEM-image of an epoxide, infiltrating a laser induced Ti nanostructure.
© Fraunhofer IFAM
EFTEM-image of an epoxide (yellow), infiltrating a laser induced Ti nanostructure.

The surface structure of a component has a major influence on its properties. Besides changing the optical appearance, surfaces can be modified at a micro and nano level in order to alter their wetting behavior and adhesion properties.

Microstructuring and nanostructuring can, for example, be used to increase the surface area that is available for the adhesion of coatings and adhesives. In combination with a specific activation step, strong adhesion forces can develop, which remain stable even under varying climatic conditions due to structure-related adhesion.

The combination with a hydrophobic surface treatment enables the generation of stain resistant,ultrahydrophobic surfaces (similar to the lotus effect). These can be used for anti-icing applications and also for the separation of liquid mixtures.

Hydrophilic and ultrahydrophilic surfaces are also possible. Such surfaces, for example, open up opportunities for directed or accelerated liquid transport and also for generating anti-fog properties.

Furthermore structured component surfaces allow customization of the friction and abrasion properties. For example, in lubricated systems it is possible to rapidly attain the desired hydrodynamic properties. Haptic changes and also the manufacture of effective catalytic surfaces are other potential areas of application. Amazing phenomena in nature involving microstructuring and nanostructuring often provide the basis for the development of innovative new technical products.

Research on the microstructuring and nanostructuring of surfaces

Water droplet on heat exchanger with superhydrophobic coating.
© Fraunhofer IFAM
Water droplet on heat exchanger with superhydrophobic coating.

An overarching aspect of the R&D work of Fraunhofer IFAM in this area is the development of strategies and solutions for ensuring the stability of the relevant functional structures (microstructures and nanostructures).

The team at Fraunhofer IFAM on the one hand develops material-specific technologies for surface structuring. Various plasma methods and laser technologies are used for this. On the other hand, they also focus on surface functionalization under retention of the surface topography (e.g. via thin film coatings). A range of technologies is available and can be combined as desired for specific products and materials. These are selected with a view to favorable-cost series production.

 

Benefits:

  • Wetting behavior and adhesion properties can be customized
  • Wide range of technologies for application on different materials
  • Tailoring of the surface properties via microstructuring and/or nanostructuring
  • Processes can be scaled up for industrial applications

Technologies: