The Synergy Between The Claws And Adhesive Pads Of Insects

The excellent attachment and locomotion abilities of insects strongly depend on their attachment devices. Researches of their evolved devices not only help to understand their attachment mechanisms, but also inspire engineers to design and promote the bio-inspired attachment devices.Recent studies indicated that animals’ single attachment organ are insufficient for reliable attachments, so the synergies between the different attachment organs may play an important role.To study the synergy between the claws and adhesive pads of insects and explore the effects of large substrate protrusions. A biomimetic attachment device which consists of two claws and an adhesive pad was designed and a serial of steel spheres were chosen as the substrate protrusions. The attachment performances were tested on a multi-functional test system.Except for the extreme interaction forces, the corresponding dissipated energies of artificial devices on different substrates were also calculated. The synergy between the claws and the adhesive pad and the effects of protrusion scales were discussed subsequently. With the increase of protrusion diameters,both of the claws and the structure contain claws and adhesive pad degraded, while the adhesive pad works better and better. Comparisons demonstrated that the claws were able to generate sufficient forces if the protrusions were relative small and the adhesive pad contributed much to the need forces if the protrusions were very large. The adhesion forces generated at the pad increase the frictional forces and this frictional forces enhanced the adhesive pads in shearing strengths in return.At last, we established a mechanical model to explain the above mentioned synergy. Additional, the influences of other relative parameters were discussed within the model.