Geckos can stick to surfaces because their bulbous toes are covered in
hundreds of tiny microscopic hairs called setae. Each seta splits off
into hundreds of even smaller bristles called spatulae. Scientists
already knew that the tufts of tiny hairs get so close to the contours
in walls and ceilings that the van der Waals force kicks
in. This type of physical bond happens when electrons from the gecko
hair molecules and electrons from the wall molecules interact with each
other and create an electromagnetic attraction...
A gecko by definition is not sticky — he has to do something to make
himself sticky," study lead author Alex Greaney, a professor of
engineering at Oregon State University in Corvallis, told Live Science.
"It's this incredible synergy of the flexibility, angle and
extensibility of the hairs that makes it possible."
Greaney and a team of researchers created a mathematical model that
shows how the setae angle and the forces that act on a gecko as it
climbs interact to create a delicate but powerful sticking system.
Additional explanation at
LiveScience. Photo
via.
one can take advantage of such forces. for example, walking very close to a wall, so close that one is almost brushing against it. as a result of being so close, one walks faster. of course, being too close to the wall, and actually brushing against it, causes friction, which negates the effect and slows one down.
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