Achema 2018: Researchers take a closer look at drops using 3D high-speed camera technology
At a lotus leaf, drops simply roll off, but a concrete wall is wetted by them. The reason for this lies in the condition of the surface. Tiny structures are the reason for drops not to adhere to the surface. Researchers at the Technische Universität Kaiserslautern (TUK) are investigating this effect using a 3D high-speed camera system. This helps them to see what happens when drops hit difference surfaces. The findings could help to reduce machine wear and tear or to keep plants free of contamination.
During the Achema, a trade fair for the process industries in Frankfurt, they are presenting this technology at the research stand of the federal state Rhineland-Palatinate from June 11-15 (hall 9.2, stand A86a).
If drops of water fall on a lotus leaf, they simply roll off. This phenomenon, also known as „lotus effect“, is based on the fact that the surface of those leafs shows unevenness (nubs) which in the end makes the drop roll off. The tiny structures were discovered by the botanist Wilhelm Barthlott in the 1970s thanks to a scanning electron microscope. The very same principle is now used for window glass or wall paint.
Researchers of the Department Mechanical and Process Engineering at the TU Kaiserslautern engage in this this phenomenon. They investigate the behavior of drops when they encounter surfaces which provide differently formed micro structures, such as nubs, grid or trapezoid. „Here we deal with structures that are significantly smaller than the diameter of a hair, for example,“ says Fabian Krull, who investigates this topic within the scope of his doctorate at the Department of Particle Process Engineering of Professor Dr. Sergiy Antonyuk. They are in a range of 100 nanometer and 10 micrometer; dimensions not visible to the human eye. And still those structures can influence the impingement of drops on a surface in different ways.
In order to be able to observe this process in detail, three high-performance cameras are used. „They take pictures from different angles“, says Fabian Krull. Software is used to then convert the data to a 3D picture. „That way we can observe step by step what happens when a drop hits different surfaces“, explains Professor Antonyuk. Furthermore, the engineers simulate the fall of those drops with their computer models.
Research is carried out within the framework of the Collaborative Research Centre 926 „Component Surfaces: Morphology on a microscale“, which is subsidized by the German Research Foundation. The researchers‘ findings might be able to help reduce friction of machines or design surfaces of industrial plants to prevent dust and contamination particles to accumulate on the machines. This would also be useful for hospitals so that microorganisms cannot adhere to certain things.
The engineers are presenting their camera system and research work at the Achema.
Questions can be directed to:
Prof. Sergiy Antonyuk
Phone: +49 (0) 631 205-3524
Klaus Dosch, Department of Technology and Innovation, is organizing the presentation of the researchers of the TU Kaiserslautern at the fair. He is the contact partner for companies and, among other things, establishes contacts to science.
Contact: Klaus Dosch, Email: dosch[at]rti.uni-kl.de, Phone (also during the fair): +49 (0) 631 205-3001