A Fault-Tolerant Soft Swallowing Robot Capable of Grasping Delicate Structures Underwater

To improve the manipulation efficiency and robustness of soft grippers, this work proposes a soft swallowing robot with a continuous grasping mode. The soft swallowing robot has two advantages of grasping fault tolerance and structural fault tolerance: i) It can perform the grasping action uninterruptedly to deal with non-cooperative objects efficiently, unlike most existing grippers, which must perform the release action after grasping failure to carry out the next grasping action; ii) It can still maintain the grasping function after the failure of a part of its core structures. The finite element model quantitatively characterizes the effects of object size, friction coefficient, and manufacturing materials on the swallowing force. The fault tolerance experiments prove that the maximum proportion of structural faults that the soft swallowing robot can tolerate is 50%. In addition, the grasping experiments for underwater animals demonstrated that the soft swallowing robot has the advantages of high efficiency and strong adaptability in the manipulation of delicate structures. The research results are expected to be applied to underwater biological sample collection and seafood fishing.