Humans can now climb smooth glass walls thanks to geckos and DARPA

Stream:

News Bot

Your News Bitch
3,282
0
0
0
Console: Headset:
Science! By Ryan Whitwam Jun. 7, 2014 11:10 am
Your dreams of becoming Spider-Man are one step closer to reality thanks to DARPA’s Z-Man project. This is an effort to create a climbing apparatus that will allow humans to scale smooth walls and objects without risk of falling. The first tests of this new system have been successful, and it’s based not on spiders, but on the humble gecko.
The large rectangular paddles that constitute the Z-Man system don’t look much like a gecko’s foot, but they seek to replicate the same delicate structure that gives geckos their stupendous climbing ability — an ability that has long been one of the most perplexing in the animal kingdom. A gecko’s foot doesn’t secrete any kind of adhesive, yet they remain firmly planted running up walls. The answer lies not in chemistry, but in atomic-scale physics.
A gecko’s foot is covered with scores of tiny ridge structures called setae that are only 100 micrometers long. Sprouting from each setae are hundreds of small projections called spatulae that are about 200 nanometers in diameter. These hair-like structures increase the surface area of the foot by many times, allowing it to take advantage of van der Waals intermolecular forces. That’s the key to a macroscopic gecko using the sub-microscopic world as its anchor.

The van der Waals forces are weak intermolecular interactions that are much less strong than covalent or ionic bonds. Essentially, two atoms might have a slight charge imbalance, either due to their bond pattern, or as a short lived multipole moment as the electron cloud shifts around. This results in a very mild attraction, but if you add that force up across all those spatulae, it gets pretty sticky.
A gecko can use this system to dangle its 200g mass from a single toe, but scaling a van der Waals support system up to humans has been a challenge. The material on the pads was designed using nanoscale fabrication techniques to replicate the physical structure of spatulae. Tthe surface area is even larger relative to a human that the gecko’s feet are to it. The paddles have to be moved one at a time and carefully reset after each movement. Still, climbers have easily scaled 25 foot glass walls with the Z-Man system. One climber even had a 50 pound backpack on.
DARPA has been testing Z-Man technology for the last two years and hopes to see it utilized by soldiers in urban combat scenarios. Did someone say Spider-Soldiers?



More...