Gecko’s soft hairy toes reorient to help it stick to different types of surfaces

Biologists from the University of California, Berkeley, and Nanjing University of Aeronautics and Astronautics observed geckos running horizontally along walls to learn how they use their five toes to compensate for different types of surfaces.

The diminutive gecko is capable of some extraordinary feats of locomotion, zipping along vertical walls with ease and even running short distances across water. Precisely how they accomplish these feats has long interested scientists. A new paper in Proceedings of the Royal Society B reports that geckos' ability to reorient their flexible toes is a major factor, enabling them to realign and adjust to shifts in gravity (load). The work may one day help to improve the design of bio-inspired robots.

This work builds on a 2018 study from the laboratory of University of California, Berkeley biophysicist Robert Full. Geckos are known for being expert climbers, able to stick to any surface thanks to the tiny hair-like structures on the bottoms of their feet. The little lizards can also zip along the surface of water at high speeds to elude predators. They can't do it for very long; the energy expenditure required is too great. But it's amazing that they can do it at all.

As we reported in 2018, those creatures in nature capable of walking on water employ different mechanisms depending on their size. Small, lightweight water striders, for instance, rely entirely on surface tension to stay afloat, while the larger, heavier basilisk lizards employ a slapping motion with their feet that creates pockets of air bubbles to keep from sinking. The standard theoretical calculations set very strict boundaries for how small an animal has to be to use surface tension and how large it needs to be before the surface slapping mechanism is viable.

Read 6 remaining paragraphs | Comments