Gecko Toe Pads

Geckos toes are not suction cups or sticky like tape. Geckos actually have microscopic hairs on their lamellae called Setae and those hairs split into even smaller hairs called Spatulae that touch the surface and engage intermolecular van der Waals forces. Together, the 6.5 million setae on a 50-gram gecko generate enough force to support the weight of two people.

Below are some pictures, a definition of van der Waals forces and some other facts about geckos toes.

Van der Waals force is the sum of the attractive or repulsive forces between molecules (or between parts of the same molecule) other than those due to covalent bonds, the hydrogen bonds, or the electrostatic interaction of ions with one another or with neutral molecules.  The term includes:

• Force between two permanent dipoles (Keesom force)
• Force between a permanent dipole and a corresponding induced dipole (Debye force)
• Force between two instantaneously induced dipoles (London dispersion force).

 

 

·         Geckos adhere to just about any surface, wet or dry, smooth or rough, hard or soft.

·         Gecko adhesion is unique in that it is self-cleaning during repeated use.

·         Gecko adhesion can be mechanically switched on and off. Sliding against a surface uncurls the seta to engage the adhesive. By relaxing sliding tension, the adhesive can be released.

·         Geckos detach their toes by hyperextending their toes as shown below.