Geckos keep firm grip in wet natural habitat

April 1, 2013
Geckos keep firm grip in wet natural habitat

(Phys.org) —Geckos' ability to stick to trees and leaves during rainforest downpours has fascinated scientists for decades, leading a group of University of Akron researchers to solve the mystery.

They discovered that wet, hydrophobic (water-repellent) surfaces like those of leaves and secure a gecko's grip similar to the way dry surfaces do. The finding brings UA integrated bioscience doctoral candidate Alyssa Stark and her research colleagues closer to developing a synthetic adhesive that sticks when wet.

Principal investigator Stark and her fellow UA researchers Ila Badge, Nicholas Wucinich, Timothy Sullivan, Peter Niewiarowski and Ali Dhinojwala study the adhesive qualities of gecko pads, which have tiny, clingy hairs that stick like Velcro to dry surfaces. In a 2012 study, the team discovered that geckos lose their grip on wet glass. This finding led the scientists to explore how the lizards function in their .

The scientists studied the clinging power of six geckos, which they outfitted with harnesses and tugged upon gently as the clung to surfaces in wet and dry conditions.

University of Akron researchers discover why geckos keep a firm grip on leaves and tree trunks in wet natural habitat. Credit: Alyssa Stark

Link between adhesion and 'wettability'

The researchers found that the effect of water on adhesive strength correlates with wettability, or the ability of a liquid to maintain contact with a . On glass, which has high wettability, a film of water forms between the surface and the gecko's foot, decreasing adhesion.

Conversely, on surfaces with low wettability, such as waxy leaves on , the areas in contact with the gecko's toes remain dry and adhesion, firm.

"The geckos stuck just as well under water as they did on a dry surface, as long as the surface was hydrophobic," Stark explains. "We believe this is how stick to wet leaves and tree trunks in their natural environment."

The discovery, "Surface Wettability Plays a Significant Role in Gecko Adhesion Underwater," was published April 1, 2013 by the Proceedings of the National Academy of Sciences. The study has implications for the design of a synthetic gecko-inspired adhesive.

The video will load shortly
Video from the 2012 study.

Explore further: Sticky gecko feet: The role of temperature and humidity

More information: "Surface wettability plays a significant role in gecko adhesion underwater," by Alyssa Y. Stark et al. PNAS, 2013.

Related Stories

Sticky gecko feet: The role of temperature and humidity

May 14, 2008

A team of five University of Akron researchers has published the paper, “Sticky gecko feet: the role of temperature and humidity” in PLoS ONE, an open-access, online journal for peer-reviewed scientific and medical research.

Scientists trace gecko footprint, find clue to glue

August 25, 2011

Geckos' ability to scamper up walls with ease has long inspired scientists who study the fine keratin hairs on these creatures' footpads, believed responsible for the adhesion. Researchers at The University of Akron have ...

Copying geckos’ toes

September 5, 2011

Geckos are famous for their ability to walk up walls and scamper across ceilings. The dry-adhesive surface of geckos’ toes has inspired many attempts to copy this ability in an artificial material. Isabel Rodríguez ...

How geckos cope with wet feet

August 9, 2012

Geckos are remarkable little creatures, clinging to almost any dry surface, and Alyssa Stark, from the University of Akron, USA, explains that they appear to be equally happy scampering through tropical rainforest canopies ...

Recommended for you

Antiperspirant alters the microbial ecosystem on your skin

February 2, 2016

Wearing antiperspirant or deodorant doesn't just affect your social life, it substantially changes the microbial life that lives on you. New research finds that antiperspirant and deodorant can significantly influence both ...

Chromosomes reconfigure as cell division ends

February 5, 2016

Cellular senescence—when a cell can no longer divide—is a programmed stage in a cell's life cycle. Sometimes, as in aging, we wish it didn't happen so much and sometimes, as in cancer, we wish it would happen more. Given ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.