 A recent study has however shown that gecko adhesion to smooth Teflon and PDMS surfaces is mainly determined by electrostatic interaction (caused by contact electrification), not van der Waals or capillary forces.There were efforts in 2008 to create a dry glue that exploits the effect, and success was achieved in 2011 to create an adhesive tape on similar grounds.In 2011, a paper was published relating the effect to both velcro-like hairs and the presence of lipids in gecko footprints.