Gecko climbing glass

Geckos can climb smooth surfaces like glass thanks to millions of microscopic hairs on their feet that generate intermolecular forces.

About this subject

Geckos are reptiles of the family Gekkonidae renowned for their ability to adhere to vertical and smooth surfaces such as glass and painted walls. This skill has intrigued scientists for decades and inspired research into biomimetic adhesives.

The secret lies in the lamellae of their feet, which contain rows of structures called setae, each with hundreds of even smaller tips known as spatulae. These structures create such a large contact area that van der Waals forces, weak electrical interactions between molecules, become sufficient to support the animal's weight. Unlike suction cups or sticky substances, the mechanism is dry and leaves no residue.

Interestingly, geckos can release their grip by changing the angle of the setae, reducing contact and allowing rapid movement. About 60% of gecko species possess this ability, including the common house gecko (Hemidactylus frenatus), often found in urban areas worldwide. A single gecko foot can support up to 20 times the animal's body weight.

Technological applications include reusable adhesives, climbing robots, and even gloves for mountaineering. Scientists at MIT and Stanford University have developed prototypes inspired by gecko feet, but they have not yet fully replicated natural efficiency, especially on dirty or wet surfaces.

Frequently Asked Questions

How do geckos climb glass without falling?

They use millions of microscopic hairs on their feet (setae) that generate van der Waals forces with the surface, creating enough adhesion to support their weight.

Do geckos leave any residue when climbing smooth surfaces?

No. The mechanism is dry and does not involve sticky substances. They release their grip by changing the angle of the setae, leaving no marks.

Can all geckos climb glass?

No. About 60% of gecko species have this ability. Some, like those in the subfamily Eublepharinae, lack adhesive lamellae and are ground-dwelling.