Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gecko Feet Hold the Key to Self-Cleaning Adhesives

05.01.2005


Duct tape that never loses its stick. Bandages that come off without sticky residue or an "ouch."



Gecko feet may hold the key to the development of synthetic self-cleaning adhesives, according to a biologist from Lewis & Clark College. The research is published in the online early edition of the Proceedings from the National Academy of Sciences of the United States, or PNAS (http://www.pnas.org) during the week of Jan. 3, 2005 (Article #08304: "Evidence for self-cleaning in gecko setae").

"How geckos manage to keep their feet clean while walking about with sticky feet has remained a puzzle until now," said Kellar Autumn, associate professor of biology at Lewis & Clark College. "Geckos don’t groom their feet, and the adhesive on their toes is much too sticky for dirt to be shaken off. Conventional adhesives like tape just get dirtier and dirtier, but we discovered that gecko feet actually become cleaner with repeated use."


Autumn’s new research, published in PNAS, found that the microscopic adhesive hairs--or setae--that create the gecko’s adhesive qualities are also the first known self-cleaning adhesive. According to Autumn, gecko setae isolated from the gecko become cleaner by themselves.

"Our mathematical models suggest that self-cleaning in gecko setae is a result of geometry not chemistry," said Autumn. "This means that synthetic self-cleaning adhesives could be fabricated from a wide variety of materials. The possibilities for future applications of a dry, self-cleaning adhesive are enormous. We envision uses for our discovery ranging from nanosurgery to aerospace applications. Who knows--maybe a gecko-inspired robot with sticky, self-cleaning feet will walk on the dusty surface of Mars someday."

An interdisciplinary team of researchers, led by Autumn, earlier confirmed speculation that the gecko’s amazing climbing ability depends on weak molecular attractive forces called van der Waals forces, named after a Dutch physicist of the late 1800s. Van der Waals forces are weak electrodynamic forces that operate over very small distances but bond to nearly any material. Autumn’s research team rejected a 30-year-old model based on the adhesion chemistry of water molecules. Instead, the research team demonstrated that a gecko’s ability to stick to surfaces depends on geometry--not chemistry--to synthesize the world’s first gecko-based adhesive microstructure.

The setae (microscopic hairs) on the bottom of gecko’s feet are only as long as two diameters of a human hair. That’s 100-millionths of a meter long. Each seta ends with 1,000 even tinier pads at the tip. These tips, called spatulae, are only 200-billionths of a meter wide--below the wavelength of visible light. In 2002, Ronald Fearing, a researcher at the University of California at Berkeley, was able to produce two artificial hair tips, while Autumn and colleagues concluded that "both artificial setal tips stuck as predicted and provide a path to manufacturing the first dry, adhesive microstructures." Fearing’s group later made the first array of synthetic gecko hairs with long stalks (6 micron stalk) and relatively large diameters (6 micron diameter).

The team’s research is supported by the National Science Foundation and the Defense Advanced Research Projects Agency (DARPA). More information about Autumn’s research is available online at http://www.lclark.edu/faculty/autumn/pnas05.html.

| newswise
Further information:
http://www.pnas.org
http://www.lclark.edu/faculty/autumn/pnas05.html
http://www.lclark.edu

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>