The gecko’s amazing ability to stick to surfaces and walk up walls has inspired many researchers to manufacture materials that mimic the special surface of a gecko’s foot. The secret behind the gecko’s ability to stick so well is a forest of pillars at the micro-/nano-scale on the underside of the gecko’s foot. Because there are so many pillars so close together, they are held tightly to the surface the gecko is walking on by a molecular force called the Van der Waals force. This relatively weak force causes uncharged molecules to attract each other.
In an unprecedented feat, Liming Dai, at the University of Dayton, and colleagues report in the October 10th issue of Science successful construction of a gecko-inspired adhesive that is ten times stronger than a gecko, at about 100 newtons per square centimeter.
The researchers constructed their adhesive out of two slightly different layers of multi-walled carbon nanotubes. The lower layer is composed of vertically-aligned carbon nanotubes, while the upper segment–which comes into contact with the surface it is sticking to–is curly, like a mess of spaghetti.
[Source]
Chapter: Animals & Insects :: 31 October 2008
