Wednesday, December 3, 2008

How do Geckos adhere to walls ?

Dear Diary,

Yesterday while travelling I was watching some TED talks into my iphone as I am usually doing.
Although almost every talk fascinates me, I was most astonished by one simple question that Dr Robert Full asked during his talk on "How engineers learn from evolution".
This was - "How do Geckos adhere to walls ?"

Until that very moment, I always imagined that they must be using some kind of organic glue or maybe they exploit vacuum.

The possible answers (and why after scientific examination could not be true) that presented by the host were:

  1. Friction model
    Reject: Friction forces too low
  2. Electrostatics
    Reject: Use anti-static gun and still hold on
  3. Interlocking
    Reject: Used molecularly smooth surface
  4. Suction model
    Reject: Greater than 1 atm pressure and works in vacuum
  5. Wet (capillary) adhesion
    Reject: No glue glands. Sticks underwater and in dry air
I felt my jaw dropping !
How on earth these creatures are able to run through a vertical surface in full speed then ???
The surprise reached maximum levels when the right answer popped on the screen...

They use Intermolecular or Van Der Waals Force !!!!

Believe it or not, these little guys work on molecular level...

You can watch the full talk below

No comments:

Clicky Web Analytics