Designing Bandaids that Stick When Wet Based on Gecko Feet

Like Spiderman, geckos have tiny hairs on the tips of their toes that give them the ability to climb walls. Scientists are unlocking the secrets behind these adhesive structures in the hopes of designing a much-needed technology: band-aids that don’t fall off when they get wet.

Anti-wetting properties on the lizard’s toes allow them to repel drops of water, but the researchers wanted to know what happens when the geckos deal with more than just a spring shower.

The researchers tested geckos’ abilities to cling to surfaces under a variety of scenarios, including dry, misted and wet glass with and without wet toes. They placed a small, gentle harness on the reptiles’ midsection which lightly tugged on the geckos to see how much force their grip could withstand. When the animals’ toe pads were soaked, they lost much of their ability to hand on, and the same held true when the researchers increased the glass surface’s wetness. Geckoes performed worst when they contended with both wet toes and wet glass.

The team concluded that, so long as gecko feet remain reasonably dry, they can walk on wet surfaces. But if their feet get too wet, their water-repelling abilities break down.

Meanwhile, the researchers got busy designing their own version of gecko toes. They built a dry synthetic adhesive out of carbon nanotubes that already outperforms nature’s version under wet conditions. By understanding the gecko’s weak points, the researchers hope to design synthetic materials – from band-aids to super glues to medicines – that avoid those same limitations.

More from Smithsonian.com:

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Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.