杏吧原创

THE intricately patterned toe pads of large tree frogs could help engineers improve the design of road-holding tyres, claims a Scottish zoologist.

Jon Barnes of the University of Glasgow has studied the tenacity with which 14 species of Trinidadian tree frog hang on to glass surfaces as they are gradually turned upside down. He related the angle at which they fell off to their weight and the area of their toe pads.

Barnes found that the heavier frogs hung on for longer than expected, with twice as much adhesive force in their toe pads as that of the lighter species. Hyla boans, one of the larger frogs from Trinidad weighing about 40 grams, managed to stick to the glass until it had reached 120 degrees. 鈥淭heir ability to hang on surprised me,鈥� says Barnes.

The frogs hang on using the surface tension of watery mucus they exude from glands in their toe pads, says Barnes. He calls this 鈥渨et adhesion鈥� and likens it to the way that a piece of wet blotting paper sticks to glass. Other experts in biophysics have suggested that friction and suction could also be important.

But Barnes also discovered that heavier species have increasingly intricate structures of tiny grooves and ridges on their toe pads as well as the roughly hexagonal pattern that most tree frogs possess. He believes this complexity could be the key to their superior sticking power and may have practical applications. 鈥淭he pattern of the toe pads might enable us to redesign vehicle tyres to improve their road-holding ability in wet conditions,鈥� he says. 鈥淚t is certainly something that should be investigated.鈥�

Tyre manufacturers are intrigued by the idea. An understanding of how frogs hang on could very well be applied to tyre design, agrees Geoff Stewart, a spokesman for Dunlop Tyres in Birmingham. 鈥淚t could act as a catalyst for an inventor,鈥� he says.