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Scientists Discover What Makes Geckos Stick
Posted by
timothy
on Tue Aug 27, 2002 06:14 PM
from the persistence-alone-is-not-enough dept.
from the persistence-alone-is-not-enough dept.
Scratch-O-Matic writes "This story at CNN explains how gecko feet are sticky due to an electro-mechanical phenomenon rather than a chemical glue, as had been previously assumed. The gecko is one of just a few animals capable of climbing vertical and beyond-vertical surfaces that are smooth and dry. Researchers have discovered that the secret to the adhesion lies in millions of tiny hairs called
'setae.' Each hair is the width of two human hairs, and contains about 1000 little pads at the end. The pads are so tiny that they actually cling to the surface at the molecular level, due to van der Waal forces. A gecko using all of its setae and pads at the same time could support 280 pounds. Seems to me that his should be easily replicated in the coming age of nanotechnology." Other readers point to the AP story, as carried by Yahoo! and also playing at Salon.
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Scientists Developing Commercially Viable Synthetic Gecko 122 comments
Gordon from Seattle writes to mention a CNN article about a new way to hang out. A British aerospace team is working on a super-sticky substance they're calling "Synthetic Gecko". It mimics the hairs on a gecko's foot, and may eventually be developed as a reusable adhesive. From the article: "Each of the microscopic setae on a gecko's foot has a mushroom shaped cap on the end, less than one-thousandth of a millimeter across. This ensures that the gecko's foot is in very close contact with the surface beneath. The cumulative attractive force, called van der Waals force, of these setae allows the lizard to scurry up walls and ceilings, and even hang from polished glass surfaces. In 2003 scientists at the University of Manchester produced a one centimeter patch of 'gecko tape,' but neither the University of Manchester nor University of California teams managed to produce the material in a greater quantity, unlike Haq and Sargent, who have already tested areas larger than 10 centimeters-squared."
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Scientists Discover What Makes Geckos Stick
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Sponsored... (Score:5, Funny)
I'd imagine we could put the sticky note out of business if we could get markers to write on geckos with......
Re:Sponsored... (Score:5, Funny)
Maybe not... (Score:3, Funny)
Re:That would be a lot of hair area (Score:4, Informative)
here is a link to the setae
link to pictures of setae [about.com]
they are NOT the size of 2 human hairs... and actually the geckos have 2 million on EACH TOE.
link to article from may 2000 [about.com]
What year is this? (Score:5, Informative)
So... (Score:5, Funny)
It's passive too... (Score:5, Informative)
old news (Score:5, Funny)
a) how did they find out the details? Did it involve a research assistant, a glass container, a vacuum pump and a large supply of geckos?
b) How did Geckos evolve this feature? Are geckos secretly descended from a life form that can stick to the outside of space craft?
c) Alternatively, does this prove that creatures are designed rather than evolved, and the design process is a bit more like the PhD process than anything else; some little godling spends millenia working on geckos in order to submit some paper 'An alternative mechanism for achieving stickiness in creatures' only to have it discredited by a board of professors who have always used suction and thats how they believe all creatures should stick.
280 lbs. (Score:5, Funny)
Reinventing the wheel (Score:5, Informative)
BBC covered it over two years ago. [bbc.co.uk]
Probably what happened is that a major news service hired a new reporter who heard something cool and decided to write about it. But he didn't know it was old news. Like little robots, every other newspaper in the country picked up the story and published it This kind of thing happens with just about every story. It's almost like we have one giant national newspaper.
My Gecko Story (Score:5, Interesting)
I had a bad roach problem. I did'nt want to use pesticides in my home so a friend recommended a Tokay. I was open to all options so I bought a Tokay and let it loose in my home.
The roaches were gone in two days. It was lovely. I would wake up at night turn the lights on and see my little guy on a wall somewhere.
It did such a good job eating roaches that it eventually ran out of food. I had to catch it (not easy since it put up a good fight) and put in a terrarium where it happily eats crickets.
I love my little guy.
Here is a picture [goodskeleton.com] I took of my little buddy.
Wait a minute! (Score:5, Funny)
Yes they did (Score:4, Informative)
Like velcro.. peel it from one side, it doesn't take much force, try to move it all at once, it can take literally TONS of force.
bbc and cnn (Score:3)
If you're wondering about the forces involved (Score:5, Interesting)
It's an ultra-short range stickiness that applies to just about any material.
Anybody with a physics degree will be horrified by this explanation, but conceptually imagine two neutral atoms, really close. Imagine that atom A momentarily has more of its electron cloud on the side away from atom B. Then atom A will look slightly positive to atom B. A positive charge attracts electrons, so atom B's electron cloud gets redistributed toward atom A. Atom B now looks slightly negative, keeping A's electrons (better, A's electron probability distribution (better yet, we should be talking complex amplitudes and energy values)) on the far side from B.
Corrections and clarifications to the above are entirely welcome.
Re:So why can't I do it? (Score:5, Interesting)
If I understand correctly, it's because the hairs and pads are arranged so that the sticky pads can follow surface curvature down to a near-molecular level.
Most surfaces, even ones that are polished smooth, are very rough on a small scale. This roughness is actually fractal; it's not just one level of coarseness (like sandpaper), it's coarseness on many scales. Match it on one scale, and the next step finer still keeps most of the surface away from you.
So, if you put your finger on a surface, you're still not touching much of the surface, even if you press quite hard. This limits the amount of van der Waals adhesion you can get (as the effect happens over molecular distances).
A thin film of water or oil can fill the crevases and make the bonding much stronger, if you want to try sticking your fingers to things. Don't try hanging off the ceiling, though
Disclaimer: This explanation could be completely wrong. It's just the most plausible one I can think of.
Applications other than climbing (Score:3, Interesting)
* Fasteners on living, plant-based clothing. (Anyone remember the ads for the "Playtex Living Bra?" This one has a clasp the most determined teenage boy can't pry off!)
* Biologically based near-future equivalent of a Velcro Wall. You don't need a suit . .
* Security floors. Intruders walk on but they can't walk off!
What about... (Score:3, Funny)
Obligatory Mastercard bit (Score:5, Funny)
Salaries for scientists and lab assistants: $230,000
Ticket to "Spiderman": $8.50
The fact that this was discovered only after getting the idea from the Spiderman movie: priceless.
"Why now?" answered... (Score:5, Informative)
Here's a link [pnas.org] to the Autumn, et al. article, entitled "Evidence for van der Waals adhesion in gecko setae".
Gekko experiments you can do... (Score:4, Funny)
Any chance someone could post a link to the most recent "setae at home" clients?
Thanks in advance,
-- Terry