Climbing a wall vertically in the purest spider-man style is a superpower only available to small creatures, like the arachnid himself who inoculated Peter Parker with his abilities. In fact, geckos are the largest animals capable of doing so, with bare feet, without specialized claws or toes for climbing. A new study published in the scientific journal PNAS explains why: the larger the size, the climber needs increasingly larger sticky limbs , and there is a limit imposed by the laws of physics and biology.
The researchers, zoologists at the University of Cambridge, have made their calculations: a mite uses 200 times less of its body volume than a gecko to do this. If we extrapolated it to a human, the sticky part would occupy 40% of the entire surface of their body . And if we limit this projection to the front half, with which it would climb at full speed through the skyscrapers, the percentage rises to an unmanageable 80%. Our Spiderman would need some size 145 shoes to get an idea.
The problem, experts indicate, is that as the size of an animal increases, its contact area decreases: while a light ant is very “superficial”, so to speak, a blue whale is full volume, with little surface body.
This study will not only serve to develop new super-adhesive materials inspired by nature, but also to better understand how different climbing species have adapted to anatomical constrictions . Thus, for example, they have found that frogs have developed more adherent limbs, instead of increasing the body surface of contact.
