Tuesday, November 23, 2010

Stickiness of Gecko's Feet


Everybody knows that gecko’s have sticky feet. This is one of the coolest facts about them. They are able to stick and attack or cling to a surface no matter how smooth and unstuck as many times as they want to without loosing their stickiness. This is because their feet are coated in setae. These are microscopic hairs in the shape of a spatula. The reason that their stick never runs out is because the setae clean themselves. This is all done without the use of any fluid adhesives, which Kellar Autumn discovered in 2002. Now, new research from Autumn is showing us that geckos’ feet can be even sticker when they are in a humid environment. They are able to stick to surfaces better because of microscopic water droplets in between the setae and the surface they are attaching to. Capillary action causes the water to adhere to the setae, in turn, softening their feet. This is why the humid environment around geckos can cause a stickier surface on their feet. In his research, Autumn and his fellow scientists gathered samples of the setae and imitated their movement with a “robotoe” machine so it was as it would be on a live gecko. As they tested this in different environments, at different speeds and with different surfaces to attach to, they still couldn’t figure out why humidity increases the stickiness of the setae. It was a graduate student, Michael Proswe, who finally thought he saw a cause of this increase. He realized that the substance that makes up setae, keratain, gets softer in humid environments, he thought to measure the softness of the setae in different conditions. Another scientist, Jonathan Puthoff, then proved using a mathematical model that softness is related to the stickiness of the setae. This showed that instead of what Kellar had predicted, the increased attachment to surfaces was caused by an increase in softness in the setae.





The video below talks about how the setae on gecko's feet work.

4 comments:

  1. Great post Peter!
    you did a really nice job of making the post really understand and you could tell you knew a lot about the topic. Nice Work!

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  2. I thought this post was extremely interesting. The videos were very cool too.Its one of those things that you know without really thinking about. Like obviosuly you know that geicos have sticky feet, but you don't really think about why. You no what I mean? I also owned one of those geicos as a pet. It died.Great post.

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  3. Peter, great blog post. This is very interesting and reminds me a lot of a commercial for car tires which compares the stickiness of the tires to the stickiness of gecko's feet. Although, after reading this post i believe that the stickiness is unique to a Gecko's feet and something that humans will never be able to clone. Very cool post.

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  4. Peter, I really like this blog post. It's so cool! However, what if the geckos were placed in less humid climates? Would the stickiness decrease or would it maintain the same level of stick? Overall, great post! It's so fascinating.

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