Gecko-inspired glue

Geckos are able to climb walls thanks to a coating on their toes of tiny hairs, called "setae," that are tipped with flat "spatulae." The large surface area of the spatulae exploit the van der Waals force, the weak attractive force between molecules, enabling the gecko's feet to stick. For years, scientists have worked on the development of synthetic adhesives inspired by this wonder of nature. Researchers at the University of Dayton and the Georgia Institute of Technology have now made an array of artificial setae that are actually nested carbon nanotubes. Eventually, the resarchers think the material could replace solder as well as more traditional adhesives. From New Scientist:
 Data Images Ns Cms Dn14902 Dn14902-1 492 (The researchers) controlled the (carbon nanotube) growth process to make a forest of vertical nanotube trunks turning into a canopy of tangled ends on top. The curly entangled mess acts like natural spatulae – when pressed against a surface, they have a large contact area and hence a strong hold.

The new material was tested for stickiness on surfaces ranging from Teflon to sandpaper. Attached to a glass surface, a single square centimetre of it can support over 1600 grams when pulled roughly parallel to the surface.

That is roughly 10 times better than some species of gecko and three times better than the best artificial competitor.

But removing a pad of the material is simple, unlike some rival materials. Pulling it perpendicular to a surface means only the tips of the nanotubes remain in contact with the surface, and the setae will easily loosen their grip. A weight of 160 grams on a square centimetre is enough to do that.
"Gecko-grip material aims to be the end of glue"

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  1. Yay, for biomimicry and 2 billion years worth of design solutions!

    However, I’m still wary of the potential toxicity of carbon nanotubes…

  2. Replace solder?

    I know carbon can be conductive (graphite electrodes are tons of fun to play with) but isn’t a maze of microscopic carbon tubes bound to have a hell of a lot more resistance than a glob of conductive metal?

  3. There have been a number of interesting variations on this, some more successful than others. What the geckos still have on humans is keeping those pads clean as they go — none of the biomimetic surfaces tolerate contamination and don’t self-clean under use as the originals do. A decade or so of hard work and good science not up to eons of evolution quite yet.

  4. Ummmm… I hate to throw cold water on a cool idea, but what of the possibility that broken carbon nanotubes are as dangerous to our lungs as asbestos?

    Do we need more research here?

    Just being cautious.

  5. So….

    Nano-tech velcro?

    Also, given that most glue is designed to also withstand the perpendicular force, I don’t see Krazy Glue going out of business over this. Of course, those Command strips that hold pictures on your wall might…

  6. Ummmm… I hate to throw cold water on a cool idea, but what of the possibility that broken carbon nanotubes are as dangerous to our lungs as asbestos?

    Do we need more research here?

    More research never hurts, but if it were really deadly I imagine we’d see all kinds of respiratory ailments among herpetologists.

  7. I heard of this first in this TED talk by Robert Full.

    The talk is about animal movement and designing a foot. It is apparent that gecko movement is clearly superior to the human anatomy. True, it might be dangerous but same goes for nuclear power plants. Do we stop advancing because it gets too dangerous?

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