The Gecko’s ability to scuttle up vertical walls and even run around upside down on a ceiling was once the source of much controversy among naturalists. Some said that the rows of plates on the underside of the feet secreted some kind of glue – but no trace of it could be found. Others maintained that the pads created a suction. That suggestion was disproved by putting the animals on a pane of well-polished glass on which suction should work particularly well. But the animals could not maintain their foot hold at all well. Eventually, electron micrographs of the pads revealed that each carries literally millions of tiny hairs. Each of these splays out at its end into twenty or so spatulae that are so infinitesimally small that they are able to utilize that force that binds molecules together (Van Der Waals force). This force only operates between bodies that can get within molecular distances of one another, but the hairs, being so extremely small, can indeed do this. The tiny setae (microscopic spatulae) which produce an immense amount of grip when on an optimum surface (130kgs). The strong adhesion is aided by a force known as Van der Waals Force which draws molecules together (the molecules of the climbed surface and those of the foot) disengagement occurs at an angle of 30 degrees and this is achieved by curling or rotating the foot.
(Attenborough, 2008)
| Tiny setae cover the foot pads of geckos |
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| Copyright: Andrea Rinaldi |
| Various Gecko Feet |
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| Copyright unknown |
