Luca's meaningless thoughts  

Gecko adhesion

by Leandro Lucarella on 2011- 02- 22 22:53 (updated on 2011- 02- 22 22:53)
tagged adhesion, artificial, en, gecko, research, teflon, wikipedia - with 0 comment(s)

You know how Wikipedia is... One thing led to another and I ended up reading about gecko adhesion in one of its references:

How do geckos make use of the smallest of intermolecular forces to climb walls? Tiny hairs derived from the keratin in the skin on their feet create a large, compliant surface area which makes intimate contact with the substrate. One Tokay gecko (Gekko gecko) may possess several millions of these hairs, called setae. Each seta is in turn subdivided into 100-1000 smaller flattened tips, called spatulae.

Why van der Waals? Although they are the weakest type of intermolecular force, they are ubiquitous and occur between all types of surfaces. This means that the key to dry adhesion is the shape or geometry of the adhesive, rather than the chemistry. Other insects which stick by secretions (e.g. ants, beetles, flies, etc.) are much more picky about what types of surfaces they stick to. Geckos can stick to any surface, with the exception of Teflon, which was specifically engineered to prevent even van der Waals adhesion.

Even more, there is some research on synthesizing artificial gecko adhesives. Very interesting...