Dry glue is a method of adhesion based upon the naturally occurring adaptations of the feet of geckos, which allow them to climb sheer surfaces, and even glass walls.
Background
A gecko can hang on a glass surface using only one toe. This ability of geckos has been attributed to van der Waals force,[1][2] although a more recent study suggests that water molecules of roughly monolayer thickness (present on virtually all natural surfaces) also play a role.[3]
Developments
University of Akron and the Rensselaer Polytechnic Institute
Researchers announced in a paper published in the June 18–22, 2007 issue of the Proceedings of the National Academy of Sciences that using this technique they have created a synthetic “gecko tape” with four times the sticking power of a natural gecko foot.[4] Particularly effective has been a checkerboard carpet of this material, which can be peeled and re-adhered repeatedly without weakening.[5][6][7] The material is made of columns of carbon nanotubes rooted in pieces of flexible polymer. The nanotubes were grown on a silicon base and then transferred to the polymer to provide a flexible base, similar to a gecko's foot. When dried, the polymer holds the silicon base, which in turn, holds the nanotubes.[citation needed]
Stanford University and Carnegie Mellon University
In 2006, researchers at Stanford University and Carnegie Mellon University developed a gecko-like robot which uses synthetic setae to mount walls.[8]
Georgia Institute of Technology in Atlanta
On October 9, 2008, the discovery of a new type of dry glue designed to mimic gecko feet was announced. The glue is 10 times stickier than that of the gravity-defying lizards, and three times stickier than other gecko-inspired glues. Liming Dai of the University of Dayton said "It's the stickiest dry glue yet".[9]
Defense Advanced Research Projects Agency
DARPA (Defense Advanced Research Projects Agency) is also currently working on this technology to enable a soldier to scale a wall at .5 m/s[citation needed]. This project is named Z-Man. Experiments are currently under way to develop nano-adhesives using the van der Waals effect.[citation needed]
See also
References
- ^ http://www.clemson.edu/newsroom/articles/2009/august/geckos.php5
- ^ Autumn, Kellar; Sitti, Metin; Liang, Yiching A.; Peattie, Anne M.; Hansen, Wendy R.; Sponberg, Simon; Kenny, Thomas W.; Fearing, Ronald; Israelachvili, Jacob N.; et al. (2002). "Evidence for van der Waals adhesion in gecko setae". Proceedings of the National Academy of Sciences of the USA. 99 (19): 12252–12256. Bibcode:2002PNAS...9912252A. doi:10.1073/pnas.192252799. PMC 129431. PMID 12198184.
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(help) - ^ Huber, G.; Mantz, H.; Spolenak, R.; Mecke, K.; Jacobs, K.; Gorb, S. N.; Arzt, E. (2005). "Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements". Proceedings of the National Academy of Sciences of the USA. 102 (45): 16293–16296. Bibcode:2005PNAS..10216293H. doi:10.1073/pnas.0506328102. PMC 1283435. PMID 16260737.
- ^ Nanotube adhesive sticks better than a gecko's foot, PhysOrg.com retrieved 7 July 2007
- ^ http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=112442&org=NSF
- ^ Will Knight (2003-06-01). "Gecko-like robot scampers up the wall". New Scientist. Archived from the original on 2007-12-13. Retrieved 2009-05-02Template:Inconsistent citations
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: CS1 maint: postscript (link) Cites Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu. (2003). "Microfabricated adhesive mimicking gecko foot-hair". Nature Materials. 2 (7): 461–463. Bibcode:2003NatMa...2..461G. doi:10.1038/nmat917. PMID 12776092. - ^ http://www.uakron.edu/news/articles/uamain_1293.php
- ^ "Gecko-like robot scampers up the wall" (Document). New Scientist. 2006-05-23. p. 29Template:Inconsistent citations
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ignored (help)CS1 maint: postscript (link) - ^ Gecko-like glue is said to be stickiest yet, "reuters.com" 8 October 2008