The Art of Sticking

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Sticking things together is important in many areas of everyday life.  Since many animals depend on an ability to cling to surfaces for their survival, nature uses a variety of effective sticky solutions.

Organisms stick to surfaces, using both chemical adhesives and mechanical interactions, or both.  Limpets emit strings of protein goo to stick to rocks when the sea gets rough.  The gecko uses highly specialized feet to climb.

Limpets cling to rocks using a thin layer of slime for suction adhesion.  This method is similar to the one we use to stick suction cups on shower walls.  Since suction adhesion allows some movement, limpets can go hunting algae, or glue themselves down, as desired.  Limpet mucus comprises a tangle of proteins, which attract water to make a non-permanent adhesive.  When the limpet wants to stay put, this mucus becomes stickier, but when it wants to wander, the slime thins down.

Geckoes don't need glue.  They attach themselves using geometry and physical forces rather than chemistry.  Geckoes have digits that sport thousands of hairs, which branch into spatula like tips.  These tips stick to surfaces using a weak attraction, called van der Waal's force.  So the gecko can easily run up a wall.

So next time you're out of glue, think what nature does to hold things in place.