By April Garbuz, Wilton High School
The sticky surfaces found on tree frog feet are self-cleaning, according to Niall Crawford, a researcher at the University of Glasgow, who shared his findings on Sunday at the Society for Experimental Biology Annual Conference in Glasgow.
The sticky pads on tree frog toes are used to cling to surfaces, however, how these pads stayed clean from dirt was a mystery until now. Crawford explained in Science Daily:
The same factors that allow tree frogs to cling on also provide a self cleaning service. To make their feet sticky tree frogs secrete mucus, they can then increase their adhesion by moving their feet against the surface to create friction. We have now shown that the mucus combined with this movement allows the frogs to clean their feet as they walk.
Crawford and his colleagues placed the White's tree frogs on a rotating platform and documented the angles at which the frog lost its grip. Frogs with clean feet remained adhered to the platform. The experiment was then repeated with frogs whose feet were covered in dust. When these frogs lost their grip they were able to re-adhere after taking a few steps. This showed that taking a step enables a frog to clean its feet and restores its ability to adhere.
White's Tree Frogs have small hexagonal patterns on the pads of their feet, allowing parts of the pad to create friction with the surface they are standing on, while the raised parts allow the mucus to spread. This mucus is what causes the frog to stick to the surface they are attached to, and when the frog moves, it is the mucus that carries away any dirt.
If a man-made design of this could be produced, it would provide a re-useable, clean adhesive. The self-cleaning, sticky surfaces found on tree frog feet may provide a design for products such as such as medical bandages, tires, and adhesives -- especially those used in unsanitary environments.