Nav: Home

Sticky questions tackled in gecko research

December 20, 2007

Velcro, Superglue and Post-It Notes... Three things that started out as obscure inventions but are now indispensable for everyday life. So what will the next idea to stick with modern society look like" The answer may lie in the tiny toes of a humble lizard, according to a University of Calgary biologist who is trying to figure out how geckos can cling to virtually any surface, including glass.

"Unlike most creatures, geckos don't use sticky secretions to help them hang on, it's all due to the structure of their amazing skin," says professor Anthony Russell, one of the world's leading experts on the gecko family of lizards. "Figuring out how they are able to run across ceilings and walk up windows is remarkably complex but it is getting a lot of attention because of the possible technology it could yield."

The latest development in gekkotan adhesive research is a paper by Russell and U of C graduate student Megan Johnson published in the current issue of the Canadian Journal of Zoology. It's one of the only studies to look at how a gecko's unique toe pads enable it to move through its natural habitat.

"Almost all of the research that has been done has looked at how geckos can walk on glass and other smooth surfaces, but of course their feet evolved for moving over very different surfaces, Russell said. "By looking at how they climb up rocks and other natural surfaces we are hoping to gain an even better understanding of their adhesive system because coping with rough and unpredictable terrain poses quite different problems than does smooth and even ones. This calls for examining both the animals and the terrain they use at the microscopic level."

Unlike tree frogs and many insects that use some form glue-like fluid to get a grip, geckos are dry danglers. Their fan-shaped, highly flexible feet enable them to get traction on a wide range of surfaces while moving or standing, either up, down, or upside down. This gravity-defying power lies in the tens to hundreds of thousands of hair-like structures, known as setae, on geckos' toe pads. In 2000, researchers demonstrated that the large surface area of setae allow the animals to take advantage of molecular-level attraction called van der Waals forces to stick to virtually any surface. More recently, it has been shown that friction is also involved, and that these animals use a whole bag of tricks to help them adjust to circumstances from moment to moment.

By looking at the rocky habitat of a southern African species of gecko, Russell and Johnson concluded that the setae likely evolved to give geckos traction on rugged surfaces, since only a small area of each toe pad may be able to find purchase in order to maintain grip.

"It's kind of like the tire of a car," Russell explains. "You have a large area of tread but at any moment in time, there's only a tiny portion that is actually in contact with the road, and you are depending on that to do the job in a variety of circumstances."

Researchers and corporations around the world are racing to create the first synthetic "gecko glue" and the U.S. military is leading the way in trying to create gecko-inspired robots that can scale any surface.

"The goal is to create a completely dry adhesive that doesn't leave any residue behind and will remain attached as long as you apply a load to it and can be re-used an unlimited number of times," Russell said. "Once we conquer how it works it could be reasonably cheap to manufacture and the possible uses are endless."

Russell says learning from how species are designed by nature to deal with environmental challenges provides key lessons for human innovations.

"This nano-technology has been around for over 50 million years and we are only just beginning to understand how it works," he said.
-end-
For more information or to arrange media interviews, contact:

Grady Semmens
Senior Communications Manager - Research
University of Calgary
Phone: (403) 220-7722
Cell: (403) 651-2515
Email: gsemmens@ucalgary.ca

University of Calgary

Related Geckos Articles:

Bio-fuel from waste
Fuel from waste? It is possible. But hitherto, converting organic waste to fuel has not been economically viable.
Stanford engineers design a robotic gripper for cleaning up space debris
Researchers combined gecko-inspired adhesives and a custom robotic gripper to create a device for grabbing space debris.
Leaping lizards!
Many geckos inhabit trees, often living high in the canopy.
Synthetic two-sided gecko's foot could enable underwater robotics
Geckos are well known for effortlessly scrambling up walls and upside down across ceilings.
UMass Amherst polymer scientist wins international research award
Polymer scientist Alfred Crosby at UMass Amherst is part of a team that received a three-year, $1 million grant from the Human Frontier Science Program.
Frogs have unique ability to see color in the dark
The night vision of frogs and toads appears to be superior to that of all other animals.
New species: Gecko with tear-away skin
Fish-scale geckos in the genus Geckolepis are able to lose their skin at the slightest touch.
A new species of gecko with massive scales and tear-away skin
Many lizards can drop their tails when grabbed, but one group of geckos has gone to particularly extreme lengths to escape predation.
Eat and be eaten: Invasive scavengers in Hawaii alter island nutrient cycle
Researchers from the University of Georgia have found that invasive species on Hawaii Island may be especially successful invaders because they are formidable scavengers of carcasses of other animals and after death, a nutrient resource for other invasive scavengers.
How gecko feet got sticky
Timothy Higham, a biologist at the University of California, Riverside, and two colleagues have found a gecko, Gonatodes humeralis, in Trinidad and French Guiana that offers a 'snapshot' into the evolution of adhesion in geckos.

Related Geckos Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...