After Much Chewing of Cud and Cogitation, Werewolfy <Werewolfy1
@yahoo.co.uk> Spat the Words
On Aug 29, 11:34?am, "mukyuk" <a...@b.com> wrote:
A "Spider-man" suit that enables its wearer to scale vertical walls like
the
comic and movie superhero could one day be a reality, according to a
study.
Natural technology used by spiders and geckos could help a human climb
the
side of a building or hang upside down from a roof, the analysis
suggests.
The findings are published in the Journal of Physics: Condensed Matter.
Both spiders and geckos possess tiny "hairs" that allow them to stick to
surfaces.
Some studies suggest that geckos can hold hundreds of times their own
body
weight. In 2002, US research suggested this adhesion in geckos was due
to
very weak intermolecular forces.
These are produced by billions of hair-like structures of different
sizes
that are arranged in a hierarchical structure on each gecko foot.
The intermolecular "van der Waals" forces arise when unbalanced
electrical
charges around molecules attract one another.
The cumulative attractive force of billions of gecko hairs allows the
reptiles to scurry up walls and even hang upside down on polished glass.
Size effect
Professor Nicola Pugno, from the Polytechnic of Turin, Italy, has
calculated
how sufficient stickiness could be generated in the same way to support
an
adult human's body weight.
But the bigger the surface that needs to stick, the lower its adhesion
strength. So a glove able to fit a man's hand, and covered with
artificial
gecko hairs, should not be as sticky as a gecko's foot.
Luckily, the gecko only uses a fraction of the theoretical adhesion
strength
available through van der Waals forces.
"Some researchers were able to measure a [theoretical] adhesion strength
200
times higher than the adhesion strength in the gecko. But between theory
and
practical applications there is a large gap," said Professor Pugno.
"If we are able to make a surface a little bit stronger, so that the
size
effect vanishes, we might be able to make a suit with the same adhesion
as a
gecko."
The Turin-based researcher proposes that carbon nanotubes could be used
as
an artificial alternative to the gecko's hairs.
Carbon nanotubes are tiny cylinders of carbon that measure just a few
billionths of a metre across. They are ultra-strong and can be organised
into larger fibres.
Cleaning windows
Professor Pugno also outlined three properties which a real Spider-man
suit
must demonstrate.
Firstly, and most obviously, it must be able to demonstrate strong
adhesive
properties. Secondly, the suit must be able to detach easily from a
surface
after it has stuck. Thirdly, the suit must, to some degree, be able to
clean
itself.
The latter requirement is considered important because dirt particles
could
get in the way, interfering with the adhesive properties of the suit.
One way to do it is to make the suit "superhydrophobic", so that it
strongly
repels water. As water droplets are forced away from the contact areas
of
the outfit, they should wash away particles of dirt.
This property could be achieved simply by altering the geometrical
properties, or topology, of the surface.
"To have all these mechanisms working together is difficult, because
they
are in competition with one another," Professor Pugno told the BBC News
website.
"But geckos and spiders provide a natural demonstration that this can be
done."
He added that there were many interesting applications for adhesive
suits,
in areas ranging from space exploration to defence. The work could also
aid
the design of gloves and shoes for window cleaners working on tall
skyscrapers.
But human muscles are very different to those of geckos, so people would
probably suffer from muscle fatigue if they tried to stick to a wall for
many hours.
http://news.bbc.co.uk/2/hi/science/nature/6967474.stm
In his secret and deeply buried laboratory, Dr. Mondo creates the
world's first Werespider and Weregecko.
Great article Mondo.
It is quite interesting. Mondo is like a magnet for the really cutting-edge
far-out science stuff.
Ricky
.
