Geckos can climb like no other.
Each of their five-toed feet are covered with millions of tiny hairs called setae, and each of these tiny hairs branches out into billions of nanoscale fibers. The result allows a gecko to adhere to a wall with a force 1,000 times greater than needed to hang on.
Kellar Autumn, Lewis and Clark College.
Now scientists studying the gecko’s adhesive abilities at the University of California, Berkeley have had a major breakthrough, developing a sort of “gecko tape” that begins to take advantage of some of the lizard’s remarkable properties.
Published in Journal of the Royal Society Interface, and detailed on the Web, the scientists have developed an adhesive that is the first to master the easy attach and release mechanisms of the reptile’s padded feet. (See a video here.)
The new adhesive’s hard plastic microfibers, packed 42 million per square centimeter, are switched “on” and “off” by sliding. Does that mean I can go all Spiderman and climb a building? I put the question to Ronald Fearing, the Berkeley scientist leading the project. Here’s his response:
There are a couple of interesting issues for climbing a building: 1) getting enough adhesion; and 2) having controllable adhesion so you can detach and reattach.
Our current work gives us directional adhesion on smooth and clean surfaces. We get 2 newtons per square centimeter of patch, so if the material could be scaled up, you would get about 200 pounds with a square foot of material. (This is holding the person from sliding down the side of the building, not a pull-off force.)
If we look at the region of the patch which is doing useful adhesion, we get about 4 times as much holding force, so about a 6 inch by 6 inch piece could hold a person on smooth glass. But please note that the gecko has lots of redundancy! Geckos would be extinct if they tried to climb without safety factors of 10 or 100.
The short answer, then, is not quite yet unless you’re really a risk taker. But we’re darn close.