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Geckos and chemistry

Geckos are an interesting species. They climb walls and ceilings and do not seem to have any problems with it. But how can that be? PhD Mette Heidemann Rasmussen, Associate Professor Tobias Weidner and their colleagues might have come a bit closer to an answer with their new article in Biology Letters.

Frontpage of the journal, illustrating a gecko as seen from the underbelly.
The research group has also made the frontpage of the journal.

Scientists know that geckos use specialised toepads to adhere to surfaces. These toepads consist of fine hair, called setae, which are tipped with nanometer-sized platelets which make the final contact to the surface.

In other words, the geometry of gecko feet is well-known. Nevertheless, the surface chemistry of the platelets – the actual contact points – is still unknown territory. Thus, PhD Mette Heidemann Rasmussen, Associate Professor Tobias Weidner and the rest of the team decided to study this further: What atoms and molecules come together when geckos stick to surfaces? What molecules are found at the outermost surface of gecko feet?

Our lack of understanding of this atomic structure is explained by the difficulty to identify the outermost layer of molecules in the presence of many other molecules close to the toepad surface. But the scientists found a way to single out these surface molecules by using a newly developed chemical microscope, which identifies the chemical properties of surfaces. From the data, the team was able to map the surface chemistry of the toepad tissue and identify proteins and lipids as the main components of the platelets. The lipids coat the proteins and may help hydrate the protein structure, promoting the adhesive properties.

The scientists’ research will help piece together the mechanism of how geckos stick to surfaces and provide new inspiration to material scientists hoping to mimic gecko adhesion.

ITEM CONTENT AND PURPOSE
Type of study/
method
Journal article (peer reviewed)
External collaborators No external collaborators
External funding Independent Research Fund Denmark (DFF FNU 8021-00046B)

National Science Foundation (NSF grant #1202620)

German Science Foundation (Project DFG GO 995/38-1)

U.S. Department of Energy under Contract No. DE-AC02-98CH10886
Conflict of interest No conflicts of interest
Other The research group has made the frontpage of the journal
Link to the scientific article https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2022.0093
Contact information Associate Professor Tobias Weidner, Department of Chemistry and iNANO, Aarhus University. Email: weidner@chem.au.dk