Tokay gecko (Gecko gecko) feet on glass showing the arrangement of lamellae. Gecko feet use very small subdivided filaments on the lamellae to bond with their substrates at the molecular level using Van Der Waals' forces. Every square millimeter of a geckos footpad contains about 14, 000 hairlike setae, each of which is tipped with between 100 and 1000 spatulae. If a single gecko had all spatuale engaged it could hypothetically hold a weight of 133kg. Their structure has inspired scientists such as Dr. Autumn Kellar to adapt the structure for robotic designs. Gecko feet have the property of being self cleaning, very adhesive, but leaving no residue. The grip is so strong that geckos have to disengage their feet by curling their toes backwards, much like tape being peeled off glass.