Clear view in rain!
Article about friction between liquids and solids published in “Physik in unserer Zeit”
An understanding of the friction between drops and surfaces is highly relevant both in nature and in technical applications. In their popular science article, the authors Florian Geyer, Patrick M. Seiler, Doris Vollmer and Rüdiger Berger explain to readers the basics of drop movement on surfaces. Using cars as an example, the authors explain how important it is to understand the movement of drops. With this understanding, the shape of the car can be designed in such a way that the side windows and sensor surfaces remain free of water when driving in the rain without having to be removed by a windscreen wiper. On the one hand, this does not obstruct visibility. On the other hand, the recording of measurement data, which must be recorded for autonomous vehicles, is not distorted.
To explain their research topic, the scientists from Mainz and Darmstadt introduce first the basics of drop friction and the measurement technology developed at the MPI-P. In addition, the physical properties of surfaces are discussed - here, it is shown that rough surfaces can repel water better than smooth surfaces. Finally, the researchers from Darmstadt examined similar surfaces in a complex wind tunnel setup to simulate the flow conditions in a moving car. Such investigations are currently still necessary due to the lack of alternative measurement technology and therefore require a great use of metrological and material effort. With the measuring technique developed at the MPI-P, which does not require a wind tunnel, surface properties can be investigated much more precisely. The scientists hope to be able to make a significant contribution to the faster, technically better and also more cost-saving design of new vehicles in the future through the dissemination and commercialization of the measurement technology.
The exact physical relationships and measurements are described in the popular scientific article published in the March issue of "Physik in unserer Zeit".
About the authors
Florian Geyer studied chemistry in Mainz and Ithaca, New York. He has been a PhD student at the Max Planck Institute for Polymer Research since 2015 and his dissertation deals with the production and wetting behavior of superhydro- and superoleophobic surfaces. Patrick M. Seiler studied aerospace engineering at the University of Stuttgart and Virginia Tech, USA. From 2014 to 2015 he worked as a research assistant at the German Aerospace Center (DLR). Since 2015 he has been a PhD student at the Technical University of Darmstadt and his dissertation deals with shear-driven drop and trickle movements. Doris Vollmer has been group leader at the Max Planck Institute for Polymer Research in Mainz since 2003. After studying physics in Bielefeld and Utrecht, she earned her doctorate and habilitation in physical chemistry. Since 2009 she has been investigating the wetting behavior of various surfaces in Mainz. Rüdiger Berger is interested in surface and interface properties on the nanometer scale. After studying physics in Erlangen, he developed microsensors in the IBM research laboratory Rüschlikon and received his doctorate in Basel. From 1998 to 2002 he worked at IBM Speichersysteme Deutschland GmbH and then moved to the Max Planck Institute for Polymer Research in Mainz as group leader.