Adhesion of Individual Attachment Setae of the Spider Cupiennius salei to Substrates With Different Roughness and Surface Energy

Dynamic adhesion is a key ability for animals to climb smooth surfaces. Spiders evolved, convergent geckos, dry adhesive system made of setae branching into smaller microtrichia ending as spatulae. Several previous studies concentrated either on the whole claw tuft spider´s foot that consists attachment or single contact elements, with spatula-shaped tips. Here, spider Cupiennius salei was examined and morphology pretarsus fine structure were studied in further detail. Using individual fixed force sensing cantilevers, their at different angles glass substrate measured well performance substrates roughness surfaces surface energies. The results show an variability forces corresponding seta especially tip shape. shapes vary largely even neighboring pretarsal comprises approximately 2,400 setae. Regarding energy substrate, hydrophobic polytetrafluoroethylene 30% hydrophilic which points importance both van der Waals interactions hydrogen bonds adhesion.