Gecko Feet Inspire Sticky Tape

Makarand writes "Geckos have the remarkable ability to climb the most smooth surfaces and hang from glass ceilings with a single toe. Their feet are covered with millions of nanoscopic keratin hairs that can exert an intermolecular force - called van der Waals force - producing an adhesive effect on surfaces they walk on. Researchers at Carnegie Mellon have been able to mimic the adhesive ability of Gecko feet with a synthetic material that could find applications in new types of vehicle tires or allowing robots to climb walls. The material is made by using a mould created by a lithographic process and consists of a flexibile and strong substrate covered with 100 million nanoscopic hair each centimetre square. It might take several more years before Gecko tape is made commercially available to the wanna-be Spiderman, but he will have to thank the Gecko for that, not the spider."

Re:Interesting name.. haven't heard it before...

[inaeldi]

There's a good article on van der Waal forces here [chemguide.co.uk].

Unless, of course, you're just being sarcastic, in which case disregard this comment.

Re:They won't call it Gecko Tape though

[jraf]

argh. Link is here: Gecko tape [riptie.com]

More geckos

[raynet]

Same story [cnn.com] reported by CNN and commented here [slashdot.org] :)

Spiderman

[ctid]

There's a nice picture [bbc.co.uk] in this version of the article.

Re:Wow

[simong_oz]

who in turn picked it up from Nature Materials, where the full article is soon to be published. The abstract is here [nature.com] (advance online publication) and if you've got a subscription to Nature Materials you can get the full article from there.

Wonder how it compares to the berkeley gecko glues

[ron_ivi]

More on gecko glue... The nature article (below) has cool pictures of gecko feet.

http://www.nature.com/nsu/020826/020826-2.html
Aug 2002... "Researchers have created two prototype glues after confirming that geckos owe their amazing ability to scamper across ceilings and cling to polished glass solely to many thousands of tiny, spatula-tipped split hairs on their toes.hese bond weakly with the molecules in any surface on which the lizards run.

The scientists, based at the University of California at Berkeley, cast two sets of imitation gecko toe hairs. Their mould was a microfilter with which biologists usually remove bacteria from solutions. They then tipped the hairs with silicon rubber or polyester.

In the lab, both materials adhered as well to most surfaces as the natural wall-crawlers. "

http://dsc.discovery.com/news/briefs/20020826/geck o.html
"Aug. 27 [2002] -- Research into the gravity-defying acts of geckos, which can scale smooth walls in seconds and support their weight by a single toe, has led to a prototype "gecko glue" that one day may help a small robot walk surfaces in spac"

http://www.kuro5hin.org/story/2002/10/18/03840/816
Oct 18th, 2002 ... "And if it [mass producing synthetic gecko glue] doesn't, we can harvest setae from geckos as they shed their skin and setae every few months. It's not mass-production, but it would provide plenty of setae for the micro-applications."

Re:Wonder how it compares to the berkeley gecko gl

[JimDabell]

Don't forget:

• Scientists Discover What Makes Geckos Stick [slashdot.org]
• Gecko Feet and Antigravity [slashdot.org]

It's a Berkeley project!

[Onnimikki]

This work actually originates in Bob Full's [berkeley.edu] Polypedal Lab [berkeley.edu] at Berkeley. Check out this SF Chronicle article [berkeley.edu] published in 2000 to find out a little more.

Re:Interesting name.. haven't heard it before...

[dajak]

The article fails to mention that the forces were named for Johannes Diderik van der Waals (1837-1923), professor in Amsterdam, who explained a variety of unexplained phenomena observed by others relating to pressure, volume, and temperature of gases and liquids with these two forces.

Re:What about the mighty H-bond?

[AlecC]

H-bonds don-t work for this purpose. H-bonds only bond H to H, so unless the surface you want to climb has been treated in some way to cover it wil dangling Hs, there is nothing for you to bond to. Van der Waals force works between any two reasonably flat surfaces - and any surface is flat on a small enough scale, which is what this tape is exploiting.

Re:Sweet, velcro obsolete?

[Unleashd]

-----------------
But Geim admits that the current fabrication method does not lend itself easily to mass production of the tape. And a more serious concern is how to make the artificial setae durable enough to be reapplied many times, he adds.
------------------

Unfortuately it doesn't seem like it is re-usable at this point so its current usage would be very limited

Re:What about the mighty H-bond?

[Untameduk]

H-bonds can only occur between substances with hydrogen in and even then its only in special cases. They occur in compounds where hydrogen is bonded to either oxygen, nitrogen or flourine. This kind of limits what u can stick to.

Re:What about the mighty H-bond?

[simong_oz]

sorry, but you're wrong. Hydrogen bonds are a special form of van der Waals 'bonding' which happen to be much, much stronger (as the original poster pointed out) and so they get a special name. A hydrogen bond is usually considered to be when a hydrogen atom is bonded to either N (itrogen), O (xygen) or F (luorine). F is a bit of a special case since it is so electronegative that it forms a much stronger polarisation than either O or N and it forms very, very reactcive bonds - it's why hydrofluoric acid (HF) is so dangerous.

H-bonds do not bond H to H, they cause a (part of) a bond to become polarised (the electrons are effectively dragged away from the H atom), creating a very strong van der Waals force.

Van der Waals force works between any two reasonably flat surfaces

van der Waals forces work between [bonded] atoms. A surface just has a larger area so you get more bonds in "action", hence a larger force of adhesion.

and any surface is flat on a small enough scale, which is what this tape is exploiting.

no, completely wrong - the smaller the scale, the rougher the surface. That's why surface roughness (Ra, Rs, cla) measurements are all standardised to a certain length .

The gecko exploits the fact that it has a high surface contact area to mass ratio (look at the size of the pads on the feet to it's body size).

Re:Geckoman?

[sootman]

It's not Spiderman, it's Spider-man. And it's not Geckoman, it's Gecko-man. :-)

Re:wait wait

[bill_mcgonigle]

Sometimes running out of web made for a good plot device- when it wasn't overused.

It's most likely a gland that produces the web fluid. Most glands run out of fluid when they're overused. They take a while to refill.

Geckos don't stick to everything...

[MrIcee]

Living in hawaii we have plenty house geckos brah. We love our house geckos because they keep our homes insect and spider free. They stay out of the way, up in the ceilings and windows and are very cute and loveable. However, some caveats are in order when dealing with geckos:

1. Don't confuse gecko eggs for the tasty mouth freshener TicTacs... they look identical (though gecko eggs are just slightly larger) (as an aside note, don't confuse cockroach eggs for unground coffee beans).
2. Don't "lemon pledge" your fine wood interior walls... I did this and the geckos CAN NOT STICK TO THE WALLS for about 6 months. I unfortunatly killed my entire house gecko population a few years ago due to trying to lemon oil my walls to keep them in good shape. Gecko's couldn't stick. They'd jump up to the wall and slide down. Most of 'em died cause they couldn't get to food. Took about a year to get the population back.