adhesives from biomimicry: on gecko feet

gecko feet have gazillions of microscopic hairs

Turns out, the gecko has a bit of nanotech in its tiny little feet, and figuring out how geckos walk on the ceiling is about to yield benefits for adhesive manufacturers (via sci fi tech).

The news from various nano labs is that we can create carbon nanotubes that mimic the tiny hairs on gecko feet and can be made into tape that is actually 4 times stronger than a gecko (via ars technica).

Wudja believe a square centimeter is sufficient to support nearly four kilograms? Now that's some sticky sh_t!

According to Stephen Palter, "the cumulative attractive force, called van der Waals force between hair, mushroom, and surface sticks the little guy down. If a gecko stuck every single little sticker to a surface at one time it could hold up a 250 lb man."

The key design scheme, says ars technica's John Timmer, is bundling the nanotubes in hierarchical clusters, just like the gecko does it.

Gecko feet are covered with millions of microscopic hairs with mushroom-shaped caps on the end, and this ensures that the foot is in very close contact with the surface beneath.

An experimental adhesive tape with these properties can create many individual points of failure that have to be overcome before the surface peels away.

Apparently, the only downside is what happens when you overload the tape.

Says Timmer, "the failures tend to be catastrophic, and many of the fibers break and are left behind on the surface. Long term, this will degrade the performance of what is an otherwise reusable adhesive."

Oh, and, Jonathan Gitlin reports that "increasing humidity also increases adhesion, and the more hydrophilic the surface, the more adhesion."

So, it's not just a matter of close proximity, but also a suction thang working with the moisture.

Now ya know.

Published by Ken on July 6th, 2007 tagged Systems Thinking

Comments are closed.