Micro Matterhorn Proofs Mass Produced Structured Surfaces Could Be The Future

Swiss researchers at the Paul Sherrer Institute (PSI) managed to produce a 3D model of the Matterhorn the size of a few micrometers.

To produce the structure the team utilised the two-photon lithography technology which kind of works like SLA but with very detailed light sources, so detailed that the diameter of the small Matterhorn´s summit is just 100 nanometers in diameter.

With this technology the researchers want to make surface finishes possible that mimic surfaces seen in nature. These nano surfaces could be used to produce less friction of the processed surfaces.

“You can observe these kinds of properties in nature,” explains Helmut Schift, leader of the research project at the PSI. “For example, many species of snakes are able to glide over sand without significantly wearing down their skin.” The skin of these snakes has scales and ridges just a few thousandths of a millimetre high. This strongly reduces friction in one direction. “One could imagine,” Schift continues, “furnishing machine parts that are exposed to powerful stresses through friction with a similarly structured surface. That would sharply reduce the component’s wear and tear.”

Electron micrograph of a 3-D model of the Matterhorn. The bar indicates a length of 10 micrometres, that is, one hundredth of a millimetre. (Figure: Paul Scherrer Institute)

PSI researcher Robert Kirchner at the laser device used to produce the Matterhorn models, each of which was only around seven hundredths of a millimetre in size. The researcher wears a protective suit that shields the device and the samples from dust and hair. The room is illuminated in yellow because the models are made from a material that is light-sensitive but not affected by yellow light. (Photo: Paul Scherrer Institute/Mahir Dzambegovic)

“We make the structures out of a light-sensitive material,” explains Robert Kirchner, a scientist at the PSI. “In places where the illumination is especially intense, the initially fluid material becomes hard, and the remaining material can be washed away. To expose the material, we use a special laser whose beam is only intense enough to alter the material at the focal point of a lens. We move this focal point through the material. Thus we can determine, for every individual nanometre-sized point, whether the material will wash away in the end or stay put. In this way we can fabricate almost arbitrarily complex objects with nanoscale details.”