van der Walls a.k.a. Spiderman!
First fabricated gecko tape! Just think of the
possibilities. A couple pieces on your hands and feet and you could climb
anything!
Scientists in the UK have created a sticky
tape which works in the same way as gecko feet.
Geckos
are known for their climbing prowess The
researchers say the material clings so well to a surface that by covering the
palm of one hand with the tape, a person could hang from the ceiling - just like
the remarkable lizard. So far, however,
Professor Andre Geim and colleagues have only been able to make a very small
square of their gecko tape because of the difficulties involved in the
fabrication process. Nonetheless, the
University of Manchester scientists are confident they can refine their work so
that commercial quantities of the new sticky material can be produced.
Hairy feet
'DOES WHAT A
SPIDER CAN'
Spiderman
toy hangs from glass plate The 40g toy has
gecko tape on hand 0.5cm-square tape should
hold 100g and more It is three
years since a team from California cracked the secret of how geckos are able to
perform extraordinary climbing antics.
The researchers confirmed that tiny
intermolecular forces - so called van der Walls forces - were produced by
literally billions of tiny hair-like structures, or spatulae, on each gecko toe.
These forces, which arise when
unbalanced electrical charges around molecules attract one another, allow the
animal to scurry up walls and even hang upside down on polished glass.
Now, the British researchers have
managed to create an artificial version of the spatulae.
Spider hands
They have fabricated arrays of
plastic pillars that are little more than two thousandths of a millimetre tall;
the spacing of the pillars is on a similar scale.
They are attached to a flexible base
that moves to bring the minute synthetic hairs into contact will all the small
undulations that exist even on the smoothest of surfaces.
Synthetic
hairs: The scale bar is two microns So far, a
piece of tape just a couple of centimetres square has been produced, and,
according to Professor Geim, it is just as sticky as a the real gecko foot.
He told BBC News Online: "We
demonstrated this actually with a small toy of spiderman which we found in the
nearest shop. "We covered his hand with
the gecko tape and he can stick to horizontal glass plate from underneath."
Lab tricks
Producing the gecko tape involves
processes similar to those used in making computer chips. It is long and
expensive. "There are some problems we
have to solve before this could be used commercially; the main one is that it
doesn't stay sticky for long enough. "So
we have to solve this, and that's why we're publishing the research now in
Nature Materials. We hope some other people might be able to help us."
Professor Geim has high hopes for the
gecko tape and is convinced its remarkable properties will eventually find many
applications. "We had this idea of
making some tape the size of a hand and suspending someone outside the
laboratory window. "We decided not to do
it because it would have taken a long time and cost thousands and thousands of
pounds, and wouldn't have proved anything scientifically. But we had lots of
volunteers.
Posted: Sun - June 1, 2003 at 04:27 PM