Gecko's microscopic skin hairs may help retain moisture in dry environments

Researchers used computer simulations to test whether the nanoscale hairs, or setulae, on gecko skin reduce water evaporation. The models showed that these hairs trap air and slow moisture loss, potentially helping the lizards survive in arid environments. The finding supports the idea that these structures evolved to prevent dehydration.

The study employed computational fluid dynamics to model airflow across gecko skin patterned with setulae. Simulations revealed that the precise spacing of these nanoscale hairs creates a protective boundary layer, where escaping water molecules collide repeatedly in confined spaces before some return to the surface. This mechanism counters the intuitive concern that increased surface area might accelerate evaporation rather than slow it.

The research team at Kiel University plans experimental validation using artificial skin replicas or naturally shed gecko skin. Future work will also examine how lipids embedded in the skin contribute to water repellency. The findings support the hypothesis that setulae evolved through natural selection specifically to combat dehydration in arid habitats, appearing consistently in gecko and chameleon species from dry environments.