Dry glue

climbing glass using its natural seta A gecko can hang on a glass surface using only one toe. This ability is attributed to van der Waals force, although a more recent study suggests that water molecules of roughly monolayer thickness (present on virtually all natural surfaces) also play a role. ==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 a shear stress of 32 N/cm2, which is four times the strength of a gecko's foot. 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. 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. In February 2012 Nitto Denko developed a version of gecko tape capable of sticking at temperatures between -150 and 500°C. ==See also==