Pneumatic prehensile gripper for slender objects with embedded fiber reinforcement structures

Tendril-like structures curl around plant stalks and can be regarded as effective manipulators toward an object. The light structure has flexibility and resilience. In this project, the prehensile actuator is reinforced by fiber panels with inspiration from a tendril-like plant, and a convenient pneumatic soft gripper is fabricated for slender objects which are difficult to manipulate with normal grippers. The actuator is made of human-friendly silicone and utilizes compressed gas. The movement, stiffness, and load capacity should be improved in new designs. Therefore, inspiration is found from gelatinous fibers studied by botanists, and the cross-section structure of tendril-like plants provides a good example for soft actuators because fiber panels can be reinforced inside the actuators, with inspiration from tendril-like plant structures. In the new design, as shown in this research, a fiber-reinforced panel is inserted into the cross-section of the actuator. Meanwhile, it has little influence on the helix movement of the soft actuator. The mold is fabricated by a 3D printing method, and two-component silicone is used to make the physical model of the soft actuator. Variable materials of fibers are employed for the reinforcement panels, and experiments are carried out to obtain the important characteristics of the actuator, like movement ability and response time. With all this work, the actuator can be designed well and can form the basis for the further design of soft robots and potential manipulators. In this experiment, the actuator is tested as the gripper. Slender objects in ordinary life, like pencils, straws, and chopsticks, are manipulated by the prehensile actuating gripper, and the experimental results are analyzed and discussed.