To build the devices that enable this wall crawling ability, researchers analyzed how geckos support themselves and then improved on that already-powerful adhesive ability.
Gecko feet are covered in tiny little bristles or hairs called setae, which interact with the molecules of different surfaces to create an electric attraction called van der Waals force. This force helps the little lizards cling to vertical surfaces and even walk on some ceilings.
Part of what makes this really amazing is that the structure of these connections allows the gecko to detach and reattach their feet at will, which is the special skill that actually lets them climb up the wall and not just stick to it in one place.
At their strongest, these little hairs are able to create an insanely strong attraction. If each of the 6.5 million tiny bristles was operating at full power all the time, those little gecko feet should be able to hold up a 286-pound adult human - bigger than the average NFL defensive end .
But as Science explains , geckos can actually only lift a maximum of 4.4 pounds: The bristles on their feet can't all be used at the same time. The physical structure of the foot means that only a few small hairs can be at their stickiest at once. So on a small scale, they are incredibly powerful, but it's hard to scale up that ability to bigger and heavier objects.
A HUMAN TRICK:
Whenever humans have tried to replicate gecko climbing ability, they've run into the same problem - they can't replicate sticking power using only a tiny surface area, and it's especially difficult to create enough sticking power for something as large as a person.
But a team of engineers at Stanford figured out how to make it work.
Moveable footholds are attached to the pads, so the body weight of the climber is being supported by the adhesive pad against the wall, not by brute arm strength.
In the new contraption, the two hand pads are all that hold the climber (lead study author Elliot Hawkes in the image attached) in the attached photo. The footholds he stands on are connected to those hand pads, so that the pads themselves are holding his body weight and he doesn't have to cling to the wall using brute strength. He's actually just standing on the foot-ledges in the attached image.
Each of the two hand pads is covered by 24 small tiles. Each tile is covered in tiny silicon rubber hairs that mimic the gecko's setae, each about as tall as human hair is thick.
Those little rubber hairs, or microwedges, as they are called, can attach and detach easily without breaking down - and there's something special about their adhesive force that makes them perfect for climbing. The adhesive is designed so it becomes stickier when more force is pulling on it but it becomes less sticky if you take that force away. So by stepping on a foothold connected to a hand pad, Hawkes causes that pad to generate adhesive force and stick to the wall. To detach and climb up, he just has to take his weight off the foothold.
Gecko feet are covered in tiny little bristles or hairs called setae, which interact with the molecules of different surfaces to create an electric attraction called van der Waals force. This force helps the little lizards cling to vertical surfaces and even walk on some ceilings.
Part of what makes this really amazing is that the structure of these connections allows the gecko to detach and reattach their feet at will, which is the special skill that actually lets them climb up the wall and not just stick to it in one place.
At their strongest, these little hairs are able to create an insanely strong attraction. If each of the 6.5 million tiny bristles was operating at full power all the time, those little gecko feet should be able to hold up a 286-pound adult human - bigger than the average NFL defensive end .
But as Science explains , geckos can actually only lift a maximum of 4.4 pounds: The bristles on their feet can't all be used at the same time. The physical structure of the foot means that only a few small hairs can be at their stickiest at once. So on a small scale, they are incredibly powerful, but it's hard to scale up that ability to bigger and heavier objects.
A HUMAN TRICK:
Whenever humans have tried to replicate gecko climbing ability, they've run into the same problem - they can't replicate sticking power using only a tiny surface area, and it's especially difficult to create enough sticking power for something as large as a person.
But a team of engineers at Stanford figured out how to make it work.
Moveable footholds are attached to the pads, so the body weight of the climber is being supported by the adhesive pad against the wall, not by brute arm strength.
In the new contraption, the two hand pads are all that hold the climber (lead study author Elliot Hawkes in the image attached) in the attached photo. The footholds he stands on are connected to those hand pads, so that the pads themselves are holding his body weight and he doesn't have to cling to the wall using brute strength. He's actually just standing on the foot-ledges in the attached image.
Each of the two hand pads is covered by 24 small tiles. Each tile is covered in tiny silicon rubber hairs that mimic the gecko's setae, each about as tall as human hair is thick.
Those little rubber hairs, or microwedges, as they are called, can attach and detach easily without breaking down - and there's something special about their adhesive force that makes them perfect for climbing. The adhesive is designed so it becomes stickier when more force is pulling on it but it becomes less sticky if you take that force away. So by stepping on a foothold connected to a hand pad, Hawkes causes that pad to generate adhesive force and stick to the wall. To detach and climb up, he just has to take his weight off the foothold.
No comments:
Post a Comment