By Christina Tækker
The two students Thomas Erik Bohn Smitshuysen and Emil Christian Jensen initially intended their fourth-semester course project in Physics and Nanotechnology to be about silicon chips. But a brief look at the list of possible topics and seeing the word 'shark skin' made them change their minds. They did not know what it was about. But the word in itself was enough to arouse their curiosity. Six months later, they won second prize in the Green Challenge competition, while a marine biologist and the National Aquarium Denmark, Den Blå Planet, among others, took a strong interest in their research.
Specific application
"The Physics and Nanotechnology study programme normally focuses on microprocessors, lighting, or lasers. We didn't think about whether shark skin could be relevant to research. Therefore, we were surprised that the project soon evolved into a discussion on how to use our research for a specific purpose. We just assumed that it was a course project," says Thomas.
The aim of the project was to investigate the flow dynamics of the dermal denticles of four different types of shark skin. The dermal denticles form a number of grooves in the shark skin, thereby creating microrotations in the skin. This makes it easier for the shark to slide through the water. This knowledge can be used to design the same structure for the hulls of ships or aircraft wings or to reduce resistance, saving both money and energy.
Swimsuit with a rough surface
The two students have not yet been able to find an ideal method for reproducing shark skin. Therefore, further research is needed before shark skin can be designed for other surfaces. But it will be without the two DTU students.
"Our project ends here. However, we know that research into shark skin is not uncharted territory. In the 90s, the American aircraft manufacturer Boeing experimented with shark-like structures on aircraft wings. And the swimsuit producer Speedo has introduced a swimsuit that mimics shark skin with a rough surface. So I'm sure that one day, we'll see ships with grooved hulls," says Thomas.
Although the two students have completed their project their supervisor Associate Professor KirstinebBerg-Sørensen from DTU Physics continues the work in cooperation with new undergraduate students from DTU and with marine biologists at the University of Copenhagen and Den Blå Planet. The goal is to characterize the dermal denticles' flow patterns in further detail and to expand the studies to more shark species.
The image above shows the dermal denticles from a small spotted catshark, seen from the side. The shark skin is obtained through a collaboration with The Blue Planet and University of Copenhagen. The image was made by Thomas E. B. Smitshuysen and Emil C. Jensen at the SEM facility of Nanoteket DTU. T
The student project was advised by Kirstine Berg-Sørensen and L. Sejling Haaning, DTU Physics.