There has been great interest recently in emulating the stickiness of the gecko’s foot. The lizard uses something like a van der Waals attraction between microstructures on its feet and the (often vertical) surfaces to which it clings. Now Liangtu Qu of the University of Dayton in Ohio and colleagues have shown that a layer of carbon nanotubes can stand in for the specialized surfaces of geckos’ feet. A disordered covering layer of nanotubes then provides the anisotropy in shear strength necessary to pull away from the surface at will. The idea is to be able to pull off perpendicularly to the surface, while being able to resist the downwards force of gravity. The team can now outdo the gecko by a factor of 10 and provide up to around 100 N of stickiness per square centimetre of surface.

Further reading

L Qu et al. 2008 Science 322 238.