“Nanotechnology and surface technology” in the Faculty of Materials Engineering

Prof. Markus Hornfeck

Beauty in the details
The particles involved in nanotechnology are only a few millionths of a millimetre in size. This closeness to atomic dimensions and the huge specific surface of the particles open up a whole spectrum of new properties and require a completely new approach to the material.
The models for nanostructures come from nature: a butterfly’s wing, for example, achieves its high strength with minimal weight thanks to a delicate framework structure in the nanometre range.

Photo on the right: Fotolia, Andy Nowack

Lotus effect
The lotus effect is observed on nanostructured surfaces, which dirt particles cannot adhere to and can therefore be easily removed by water.

SEM image: Tube stumps in artificial kidneys
In artificial kidneys, micro-structuring (tube stump, above) and nano-structuring (porous tube material, below) are successfully combined.
REM image: porous tube material
REM images: ZWL Lauf 2003

Nanotechnology in materials engineering

In materials engineering, the various possibilities offered by nanotechnology are exploited to produce and create structures using, for example, ultra-fine particles, functional surfaces, and layers. These include not only the carbon black in car tyres but also the finest SiO2 particles (Aerosile®) in toothpaste.
Extremely thin functional layers on spectacle lenses can be used, for example, to selectively adjust optical properties such as colour, reflection, or transparency, and improve mechanical properties such as strength and wear.
Nanometre-thick titanium surface layers improve the biocompatibility of plastic implants. New developments include special zirconium dioxide qualities and nanocomposites made of SiC/Si3N4 or Al2O3/SiC, the benefits of which include lower manufacturing temperatures.
Knowledge of nanomaterials and the understanding of their behaviour is only possible thanks to new investigative methods, such as high-resolution scanning electron microscopy (see images) or total X-ray reflection.