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07/04/2007
More Stickiness
I hadn’t planned to write more about the gecko but a number of
items have surfaced since last week’s column on the sticky feet
of geckos and frogs. For example, I commented last week on the
GEICO gecko’s cultured accent in the TV commercials. My
brother, who lived in the UK for a year or so, e-mailed me that
the gecko’s accent actually has at least a bit of Cockney, which is
not considered “cultured”. I should have known that, having
seen My Fair Lady with Julie Andrews on Broadway. Thank
you, Conrad.
Then I learned something about the gecko I find truly weird.
According to our two grandchildren, you can look into a gecko’s
ear and see out the other side! This is something I have not
experienced but have asked my good friend and loyal reader,
Dan in Hawaii, to check this out on the geckos in his backyard.
When in Florida, I’ve seen lots of geckos but have never gotten
sufficiently up close and personal to even distinguish an ear.
Finally, an e-mail from the Materials Research Society alerted
me to a publication from the University of Akron and Rensselaer
Polytechnic Institute in the June 18-22 Proceedings of the
National Academy of Sciences. I was intrigued by the names of
the authors: Liehu Ge, Sunny Sethi, Lijie Ci, Pulickel M. Ajayan
and Ali Dhinojwala. Does this say something about the trend in
the ethnic makeup of the scientific endeavor in the U.S.?
What these workers have done is to mimic the structure of the
gecko’s sticky feet, which you may recall contain thousands of
hairs (setae), each of which end in hundreds of tinier nanohairs
(spatulas). The researchers apparently have succeeded in
patterning bundles of carbon nanotubes to simulate the setae and
individual nanotubes to simulate the spatulas. They use a
flexible polymer tape as a base for the patterned nanotubes and
claim the synthetic gecko tape is 4 times better than the gecko’s
feet as far as supporting shear stress, a measure of the
“stickiness”. Could this new adhesive be the answer to the
problem of creating a wall-climbing robot?
Finally, for some time Editor Brian Trumbore has been
suggesting that I consider writing a column every other week
instead of every week. Obviously, this is due to a concern for
my advancing maturity as I approach my 80th birthday. While I
find this suggestion appealing, for the present I plan to mix in
relatively short columns with longer ones and see how that plays
out. This is one of the short ones.
Allen F. Bortrum
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