Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanomaterials: Copying geckos’ toes

05.09.2011
Simple templating technology allows researchers to stamp out materials that mimic the adhesive properties of gecko toes

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 at the A*STAR Institute of Materials Research and Engineering and co-workers at Nanyang Technological University in Singapore1 have now made one of the closest mimics to gecko toes yet, and shown that it has the properties to match.


Artificial hairs just a few hundred nanometers in diameter mimic the adhesive surface of a gecko’s toe-pads. Copyright : Agency for Science, Technology and Research

The geckos’ ability to cling to surfaces is not due to glue but to the millions of microscopic hairs that coat the surface of their toes. Each hair has a branched, hierarchical structure—toward its tip, each fiber breaks into multiple sub-fibers, which in turn break into hundreds of fibrils 100–200 nanometers in diameter. This structure ensures a high surface area, which helps the gecko to cling to the wall. In addition, the hairs become more flexible as they become thinner, which helps to maximize the number of fibrils in contact with the wall.

Rodríguez and her co-workers have successfully mimicked this hierarchical structure through the use of an anodization technique that allows branched nanopores to be etched controllably into sheets of aluminium foil—a process they used to form templates with which to create the dry adhesive surface. These templates were stamped into sheets of polycarbonate plastic using a process known as capillary force-assisted nanoimprinting, forming a hairy polycarbonate surface.

To evaluate the qualities of the hierarchical hair structure, the researchers created two separate surfaces: one with simple, unbranched hairs; and one in which the hairs branched at their tips to form nanoscopic fibrils (pictured) closely resembling those found on gecko toe-pads. They found that the sheer adhesion force of the branched material was 150% greater than that of the linear material.

“One of the most important findings from the study is the insight of how the fibrils can be made using a simple process,” says Rodríguez. “There have been reports of other hierarchical structures fabricated in polymers, but the fabrication methods they use are rather costly and complicated and not suitable for large scale.” The relatively high cost of previous attempts is due to the way the template is made—a problem that the team have now overcome using their porous alumina template technology. “Our branched, porous template fabrication is straightforward and allows large areas of gecko-like structures to be fabricated at low cost,” she adds.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

References
Ho, A. Y. Y., Yeo, L. P., Lam, Y. C. & Rodríguez, I. Fabrication and analysis of gecko-inspired hierarchical polymer nanosetae. ACS Nano 5, 1897–1906 (2011).

Eugene Low | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6381
http://www.researchsea.com

More articles from Materials Sciences:

nachricht An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

nachricht Treated carbon pulls radioactive elements from water
20.01.2017 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>