Mainland scientists have cracked the age-old mystery of how geckos scuttle up walls, a discovery that could develop Spider-Man-like robots for military use.
Chinese Academy of Sciences associate professor Chen Shaohua and Brown University professor Gao Huajian say the key is the way the reptile manipulates tiny hairs on its feet, a mechanism they describe as 'stiff-adhere and soft-release'. The idea explains how geckos - and many insects - can perform high-speed manoeuvres while remaining firmly planted on a solid surface.
'The theoretical framework provides a foundation for developing micro-robots that can move over any kind of surface,' said Dr Chen, a 35-year-old biomechanics scientist working for the Academy's Institute of Mechanics.
The pair knew that a weak molecular force called Van der Waals' force 'stuck' the gecko's feet to the wall. A gecko's foot is covered with thousands of tiny hair-like structures called setae and hundreds of even smaller hairs called spatulae that sprout in parallel from the end of each seta.
The Van der Waals' force comes into effect when the spatulae come within nanometers of a solid surface at an acute angle, gluing molecules of the two together.
Each gecko has about a billion spatulae on each foot, giving it the potential ability to resist the downward pull of a 4kg weight.