Research On Anisotropy Stiffness Of Pomacea Canaliculata's Operculum And Design Of Bionic Flexible Robot

Today,bionics has also become a hot field in robotics research.Long-term observations have found that when the foot muscle of Pomacea canaliculata are contracted,it will drive the operculum to rapid locking and compliant unlocking,which may provide new ideas for the design of new bionic flexible robots.About adult Pomacea canaliculata species of water snails with body masses ranging from10 g to 25 g use the discoidal and multi-layered opercula to protect their soft bodies from being attacked by predators.An operculum weighs on average 0.67% of the whole body mass of a snail.In this combined theoretical,experimental and robotic study,we elucidate the water snail's(P.canaliculata)unique method of manipulating the operculum by a biological compliant mechanism with anisotropic stiffness.We focus on the water snail's(P.canaliculata)operculum,as an elliptical sheet with a layered structure,and the average thickness of each layer is 55 ± 2?m.By using confocal laser scanning microscopy(CLSM),we find the resilin is distributed between rigid layers of operculum,this special sandwiched structure.Combining scanning electron microscopy,a specialized mechanical test platform and a mathematical model,we show that the operculum and internal ridges on the shell wall can compose a natural compliant mechanism,by which the stiffness for unlocking is one-sixth of that for locking,it shows that operculum has the mechanical property of lock-unlock stiffness anisotropy.We demonstrated one such application with the operculum-inspired sealing and locking-unlocking mechanism of compliant mechanism,combined with 3D printing technology builds a biomimetic layered with compliant connection,compared with the common layered lid and the none-layered lid,have compliant connection of biomimetic layered operculum has more excellent sealing performance and mechanical properties.In this research,a pneumatic spring flexible actuator was innovatively manufactured,and the mechanical performance of the flexible robot was tested.The test results showed that the flexible robot can simulate the mechanical anisotropy characteristics of foot muscle contraction,and it can quick locking and compliant unlocking.