Ever Wonder How Gecko Stick On The Wall? We’ll Tell You

Who doesn’ot know geckos? Geckos are becoming more popular these days, especially to the pet reptile lover. Are you one of them? They are popular not only because of all the patterns and the colors that they have but also because of their ability to stick to the vertical wall, like the Spiderman! But have you ever wonder how to their hands stick to the wall? How do they do that? This article will help you out to answer the question. So let’s get started!

Ever Wonder How Gecko Stick On The Wall? We’ll Tell You

Geckos come from family Gekkonidae and have over 1000 different species with a wide range of colors variety. They are reptiles that live in tropical and temperate regions. Most of them are carnivores, who eat insects and worms. But some of them eat fruits as well. 

Just like we know, geckos can climb a vertical wall, or even hang upside down and defy the gravity just like a superhero. What is way more incredible (and used to be confusing!) is that their toes are not suction cups, their toes are dry, never leave a sticky footprint whenever they walk, but they can climb on a clean surface like glass without the need handholds! They also have the ability to control their stickiness, so what we know for sure is they are not sticky like glue or stickers, but it’s way beyond that! Studies try to learn what’s behind this ability. Turns out, they are gifted with a special structure of microscopic hairs on their toes that help them to stick their feet on and off easily. 

So how do they are able to climb walls vertically?

The secret is absolutely on their feet. Gecko’s feet has many microscopic hairs that are called setae or seta. Setae are fibrous proteins that protrude from the epidermis and it is made of B-keratin. B-keratin has an important role to keep the geckos from falling. They are. in fact, so tiny, like about 5 μm in diameter, but these chemical structures on the feet of gecko help it to increase the Van der Waals force. Have you ever heard about that terms, maybe at school? Well, for short, Van der Waals force is the distance-dependent attraction between atoms or molecules, or in gecko’s case, between the feet and the wall or any other surface.

The Van der Waals force sounds really complex…

Well, because it is! Van der Waals forces come from the interactions of molecules. When negative or positive molecules come closer to each other, the charges of the first molecule may induce the charges in the other, and draws more towards it until they are attracted to each other. The more molecules that it has, the force can become more powerful

Okay, but how do these tiny hairs work?

The seta in gecko’s toes splits off into approximately 1000 microscopic hairs which are called spatulae. Spatulae comes in the shape of an isosceles triangle on each of seta’s end, and it helps to harness the van der Waals forces. Not trying to confuse you more with numbers, but even each of the spatulae is about 200nm in size!

Whenever the setae contact with a surface, their load is supported by two components: the lateral and the vertical. The lateral component is limited by the peeling of the spatulae, while the vertical one is limited by the shear force. Studies found that the molecules from gecko hair and the electrons from the wall molecules create an electromagnetic attraction when they contact each other. This is when the Van der Waals force happens.

To impress you more, this ability can be explained with a mathematical model. The study shows that surprisingly, the setae sprouting off the bottom of gecko’s feet brach out at oblique angles, instead of straight up at 90-degree angles. The hairs only bend nearly to horizontal angle, which makes them support their weights better and increase their ability to stick themselves to the surface area. 

That is a lot to digest! So now, how do they unstick themselves? 

We know that for the gecko stick to the wall, the setae have to bend at the right angle. So from there, we can conclude that in order to unstick themselves, they have to change the setae’s angle by curling their toes away from the surface. Detaching themselves and is easy for them because not only strong but their setae are also super flexible. If they have to unstick themselves from the wall quickly, let say, when they have to jump over to another surface to run away from predators, this microscopic hair in their toes have to absorb a huge amount of energy, and then redirect the energy right away. To note, geckos can walk and climb across the surfaces, even in our skin, at any angle, as long as the surface is not too wet or covered in too much moisturize that can lead their feet to become slippery!

So for short, researchers have found that balance of forces and the angle of the gecko’s toe microscopic hairs are responsible to make gecko’s sticking and unsticking success. They do have impressive flexibility, angle, and extensibility hair!

Geckos’ incredible ability is not only important for their own sakes but also have inspired us, the human to adapt it into technologies that may help our tasks. For example, we adapt the setae system to a stitch-free way to seal wounds and sticky handheld paddles to scale walls. Those innovations keep on growing along with the study the gecko’s feet because there is still a lot of unexplained stuff that we have to learn about it. Who knows we can learn so many things and even built innovative technologies from an animal, like a gecko, right? Maybe one day we have a sticky glove that let us become like a spiderman!