Nanotube adhesive sticks better than a gecko's foot

June 19, 2007
Nanotube adhesive sticks better than a gecko's foot
Microfabricated aligned multiwalled carbon nanotube setae and spatulas. (A) Optical picture of gecko foot showing that the setae are arranged in many lobes along the foot. (B) SEM image of natural gecko setae terminating into thousands of smaller spatulas. (E–H) SEM images of synthetic setae of width 50 (E), 100 (F), 250 (G), and 500 (H) µm. (C and D) Side views (C) and higher magnification SEM image (D) of the 100 µm setae. Image courtesy of the University of Akron.

Mimicking the agile gecko, with its uncanny ability to run up walls and across ceilings, has long been a goal of materials scientists. Researchers at Rensselaer Polytechnic Institute and the University of Akron have taken one sticky step in the right direction, creating synthetic “gecko tape” with four times the sticking power of the real thing.

In a paper published in the June 18–22 issue of the Proceedings of the National Academy of Sciences, the researchers describe a process for making polymer surfaces covered with carbon nanotube hairs. The nanotubes imitate the thousands of microscopic hairs on a gecko’s footpad, which form weak bonds with whatever surface the creature touches, allowing it to “unstick” itself simply by shifting its foot.

For the first time, the team has developed a prototype flexible patch that can stick and unstick repeatedly with properties better than the natural gecko foot. They fashioned their material into an adhesive tape that can be used on a wide variety of surfaces, including Teflon.

Pulickel Ajayan, the Henry Burlage Professor of Materials Science and Engineering at Rensselaer, and Lijie Ci, a postdoctoral research associate in Ajayan’s lab, created the material in collaboration with Ali Dhinojwala, professor of polymer science at the University of Akron, and University of Akron graduate students Liehui Ge and Sunny Sethi.

“Several people have tried to use carbon nanotube films and other fibrous structures as high-adhesive surfaces and to mimic gecko feet, but with limited success when it comes to realistic demonstrations of the stickiness and reversibility that one sees in gecko feet,” Ajayan said. “We have shown that the patchy structures from micropatterned nanotubes are essential for this unique engineering feat to work. The nanotubes also need to be the right kind, with the right dimensions and compliance.”

“Geckos inspired us to develop a synthetic gecko tape unlike any you’ll find in a hardware store,” Dhinojwala says. “Synthetic gecko tape uses ‘van der Waals interactions’ — the same interactions that hold liquids and solids together — to stick to a variety of surfaces without using sticky glues.”

The material could have a number of applications, including feet for wall-climbing robots; a dry, reversible adhesive in electronic devices; and outer space, where most adhesives don’t work because of the vacuum.

Source: Rensselaer Polytechnic Institute

Explore further: If you throw a gecko at Teflon, will he stick? University of Akron researchers found the answer

Related Stories

UA synthetic gecko foot-hairs leading to reusable adhesives

August 15, 2005

The interest of University of Akron polymer researchers in the fascinating ability of geckos to climb any surface and hang from just one toe soon could lead to advances in adhesives used in microelectronics and space applications. ...

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 ...

Geckos keep firm grip in wet natural habitat

April 1, 2013

( —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.

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 ...

Recommended for you

Elephant and cow manure for making paper sustainably

March 21, 2018

It's likely not the first thing you think of when you see elephant dung, but this material turns out to be an excellent source of cellulose for paper manufacturing in countries where trees are scarce, scientists report. And ...

Smallest ever sieve separates atoms

March 20, 2018

Researchers at The University of Manchester have discovered that the naturally occurring gaps between individual layers of two-dimensional materials can be used as a sieve to separate different atoms.

Quantum bits in two dimensions

March 20, 2018

Two novel materials, each composed of a single atomic layer and the tip of a scanning tunneling microscope, are the ingredients for a novel kind of quantum dot. These extremely small nanostructures allow delicate control ...

Rubbery carbon aerogels greatly expand applications

March 19, 2018

Researchers have designed carbon aerogels that can be reversibly stretched to more than three times their original length, displaying elasticity similar to that of a rubber band. By adding reversible stretchability to aerogels' ...


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.