Dry glue: Difference between revisions

'''Dry glue''' is a method ofan [[adhesion]] product based upon the naturally occurring [[adaptationsadaptation]] of the feets of [[gecko]]s,' feet that allow them to climb sheer surfaces, andsuch evenas vertical glass walls. A variety of syntheticSynthetic equivalents have been developed, usinguse [[carbon nanotube]]s to createas [[synthetic setae]] on reusable adhesive patches.

A gecko can hang on a glass surface using only one toe. This ability of geckos has beenis attributed to [[van der Waals force]],<ref>[{{Cite web |url=http://www.clemson.edu/newsroom/articles/2009/august/geckos.php5 |title=Researchers discover how geckos know when to hold tight<!-- Bot generated title -->] |access-date=2009-11-08 |archive-date=2010-06-11 |archive-url=https://web.archive.org/web/20100611153743/http://www.clemson.edu/newsroom/articles/2009/august/geckos.php5 |url-status=dead }}</ref><ref>{{cite journal|last1=Autumn|first1=Kellar|authorlink2author-link2=Metin Sitti|last2=Sitti|first2=Metin|last3=Liang|first3=Yiching A.|last4=Peattie|first4=Anne M.|last5=Hansen|first5=Wendy R.|last6=Sponberg|first6=Simon|last7=Kenny|first7=Thomas W.|last8=Fearing|first8=Ronald|last9=Israelachvili|first9=Jacob N. ''et|last10=Full|first10=R. alJ.''|year=2002|title=Evidence for van der Waals adhesion in gecko setae|url=| journal=Proceedings of the National Academy of Sciences of the USA|volume=99|issue=19| pages=12252–12256|doi=10.1073/pnas.192252799|pmid=12198184|pmc=129431|bibcode=2002PNAS...9912252A |display-authors=3|doi-access=free}}</ref> although a more recent study suggests that water molecules of roughly monolayer thickness (present on virtually all natural surfaces) also play a role.<ref>{{cite journal |last1=Huber |first1=G. |last2=Mantz |first2=H. |last3=Spolenak |first3=R. |last4=Mecke |first4=K. |last5=Jacobs |first5=K. |last6=Gorb |first6=S. N. |last7=Arzt |first7=E. |year=2005 |title=Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements|url=| journal=Proceedings of the National Academy of Sciences of the USA |volume=102 |issue=45| pages=16293–16296 |doi=10.1073/pnas.0506328102 |pmid=16260737 |pmc=1283435 |bibcode=2005PNAS..10216293H |doi-access=free}}</ref>

In 2007, researchers from the [[University of Akron]] and [[Rensselaer Polytechnic Institute]] announced they had developed a form of flexible, reusable [[gecko tape]] using [[carbon nanotube]]s to create microscopic [[synthetic setae]] and [[spatula]]e capable of supporting supporting a [[shear stress]] of 32 [[Newton (unit)|N]]/[[Metre|cm]]², which is four times the strength of a gecko's foot.<ref>{{citeCite pmidjournal | 17578915}}</ref> In 2008 researchers from the [[University of Dayton]] reported a gecko glue capable of supporting 100N/cm², ten times the strength generated by a gecko's foot. The research also used carbon nanotubes, but included a curled end which allowed stronger binding but easy removal.<ref>{{cite pmid | 18845750}}</ref> [[DARPA|Defense Advanced Research Projects Agency]] (DARPA) has a project called "Z-Man" that is attempting to develop a fabric allowing soldiers to scale vertical walls while carrying a full combat load.<ref>{{cite web | url = http://www.darpa.mil/our_work/DSO/programs/Z_man.aspx | title = Z-man | publisher = [[DARPA]] | accessdate = 2012-07-27 | last = Goodman | first = M }}</ref> In February, 2012 [[Nitto Denko]] developed a version of gecko tape capable of sticking at temperatures between -150 and 500°[[Celsius|C]].<ref>{{cite press release|title=Nitto Denko's "Gecko Tape" achieves precise, contamination-free analysis service in the -150- 500°C range | publisher = [[Nitto Denko]] | date = 2012-02-24 | accessdate = 2012-07-27 | url = http://www.nitto.com/news/20120224/index.html }}</ref>