Synthetic gecko toes. Toes from a robot foot designed to mimic (biomimetics) the foot of a gecko. The robot foot is made of a dry adhesive polymer. The complete structure also includes hooks, which allow the robot to climb on vertical walls without falling off. Geckos are able to climb on vertical walls and ceilings due to weak intermolecular forces (van der Waals forces) created by the microscopic hairs under their feet. On each step, the gecko first uncurls it's toes to make contact, then unpeels the foot to take the next step. This uncurling and peeling action can be performed up to 15 times per second. Photographed in 2005 at Stanford University, USA.