I have always liked geckos. They are fascinating creatures that have inspired people for ages. There are even old myths that say, if you see a gecko, it means that you are safe and someone is watching over you.
Today, people are asking different questions about geckos. One of the most obvious ones is, how do they stick to walls?
Gecko feet are covered in half a million tiny, velvety hairs called setae. These hairs give their feet their huge adhesive strength. At the tip of each hair there are even smaller fibers called spatulae. These spatulae use intermolecular forces that are not quite magnetism, but are a charged attractions call Van der Waals forces, that allow the foot to stick to almost any surface. The contact between the foot and the object that the gecko is sticking to is so close that the foot almost becomes a part of the object. Setae are only part of the story, though. If the gecko is to stay on the surface that it is on, it has to place its feet on it in a precise way. If a person were to move the surface that the gecko was standing on and the gecko were not able to adjust its feet quickly enough, it would, surely, eventually, fall off. It is both the setae and the placement of the gecko’s foot that allows it to stick to the wall.