Scientists at Oregon State University have discovered more details on how geckos are able to stick the soles of their feet onto surfaces, allowing them to climb vertically or hang from a ceiling.

How Geckos Stick To Surfaces

In a new paper published in the Journal of Applied Physics, scientists explore how the gecko’s foot structure allows it to both stick and unstick itself from a surface with the same level of ease. According to previous research, a gecko’s foot is covered in miniscule folds and tiny hairs, whose tips, called setae, are incredibly flexible.

These setae provide millions of little spots that harness a molecular force to adhere to a smooth surface. Alone, each seta only provides a minimal amount of force, but because the gecko’s foot holds millions, the combined force allows gecko’s to move vertically and hang upside down.

Geckos' Setae

What makes geckos so singular, is their ability to control the force and move quickly, and that is where the setae’s flexibility comes into play. According to the study, the gecko’s ability to change the angle of the setae, or the angle of the molecular force, allows it to unstick and stick so quickly.

“The angle allows it to turn the stickiness on and off,” explained Alex Greaney, the lead author of the paper.

Greaney and his team created a mathematical model to illustrate the relationship between the angles of the setae and the amount of grip, or stickiness.

“A gecko by definition is not sticky. He has to do something to make him sticky. It’s this incredible synergy of the flexibility, angle and extensibility of the hairs that makes it possible,” Greaney said.

Unfortunately for those who hope to mimic the gecko technology, Greaney says that the gecko’s adhesive abilities are directly related to their size.

“The system is hierarchical – there are four legs, then toes, then flaps of skin, then hairs that branch and branch again – all this must be balanced with other stages of hierarchy and the muscular physiology of the gecko,” Greaney added.