Monday, August 6, 2007

Gecko Glue

"The remarkable adhesive abilities of geckos and mussels have been combined to create a super-sticky material.

Unlike other adhesives inspired by the nimble reptiles, "geckel" can attach to both wet and dry surfaces, the team that developed the material says.

Its staying power comes from coating fibrous silicone, similar in structure to a gecko's foot, with a polymer that mimics the "glue" used by mussels."

"Geckos have an incredible ability to stick to surfaces. Some studies suggest the over-engineered reptiles can hold hundreds of times their own body weight.

In 2000, a University of California team showed that the adhesion was due to very weak intermolecular forces produced by the billions of hair-like structures, known as setae, on each gecko foot.

Geckos can support hundreds of times their own body weight
These "van der Waals" forces arise when unbalanced electrical charges around molecules attract one another.

The cumulative attractive force of billions of setae allows geckos to scurry up walls and even hang upside down on polished glass.

The reptile's grip is only released when it peels its foot off the surface.

The new geckel material exploits this ability but also combines it with the sticking power of mussels.

It consists of a base of densely packed silicone setae coated with a polymer that mimics amino acids found in the glues of mussels."