Geckos have the gravity-defying ability to climb smooth walls and hang from the ceiling by a single toe, thanks to the intermolecular(分子間の)van der Waals forces(ファン・デル・ワールス力)that give the microscopic(極微細な)hairs on their toes incredible adhesive properties. Scientists, fascinated with the idea of creating a super-sticky dry glue that can easily be lifted and reapplied, have studied the gecko’s spatula-tipped(先がへらの様な)setae(剛毛、とげ)and developed an adhesive(粘着性物質)based on nature’s design. The newest version, made from carbon nanotubes that mimic the lizard’s microhairs, is 10 times stickier than a gecko’s feet; a mere 1-in (2.5-cm) square can support the weight of a 220-lb (1-kg) man climbing a vertical surface.