Dry glue is a method of adhesion based upon the naturally occurring foot adaptations that allow geckos to climb sheer surfaces and even glass walls. A variety of synthetic equivalents have been developed, using carbon nanotubes to create synthetic setae on reusable adhesive patches.
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
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 nanotubes to create microscopic synthetic setae and spatulae capable of supporting supporting a shear stress of 32 N/cm2, which is four times the strength of a gecko's foot.[4] 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.[5] 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.[6] In February, 2012 Nitto Denko developed a version of gecko tape capable of sticking at temperatures between -150 and 500°C.[7]
See also
References
- ^ Researchers discover how geckos know when to hold tight
- ^ 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.
{{cite journal}}: Explicit use of et al. in:|first9=(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.
- ^ Attention: This template ({{cite pmid}}) is deprecated. To cite the publication identified by PMID 17578915, please use {{cite journal}} with
|pmid= 17578915instead. - ^ Attention: This template ({{cite pmid}}) is deprecated. To cite the publication identified by PMID 18845750, please use {{cite journal}} with
|pmid= 18845750instead. - ^ Goodman, M. "Z-man". DARPA. Retrieved 2012-07-27.
- ^ "Nitto Denko's "Gecko Tape" achieves precise, contamination-free analysis service in the -150- 500°C range" (Press release). Nitto Denko. 2012-02-24. Retrieved 2012-07-27.