Abstract: The pneumatic gripper in industrial applications has the advantages of structure simplicity and great adaptability, but its gripping power is usually limited due to the low modulus of soft materials. To address this problem, a novel bionic pneumatic gripper inspired by spider legs is proposed. The design has two pairs of symmetrical fingers, each finger consists of two pneumatic actuated joints, two rigid links and one pneumatic soft pad. The rigid link connects the pneumatic chamber which is enclosed in a retractable shell to increase the actuation pressure and the gripping force. The compressibility and elasticity of the soft joint and pad enable the gripper to grasp fragile objects without damage. The modeling of the bionic gripper is developed, and the parameters of the joint actuators are optimized accordingly. The prototype is manufactured and tested with the developed experimental platform, where the gripping force, flexibility and adaptability are evaluated. The results indicate that the designed gripper can grasp irregular and fragile items in sizes from 40 to 140 mm without damage, and the lifting weight is up to 15 N.

Key words:  , Pneumatic , actuation , · Bionic , soft , gripper , · Theoretical , modeling , · Joint actuator