A Soft Grasping Device with the Modularization and Bi-directional Bending Properties

This work proposes a fully soft grasping device to perform complex tasks, which consists of the modularized soft grippers and the bi-directional bending soft holder. In the modularized soft gripper part, we adopt caps to seal both ends of the gripper and connect the adjacent knuckles by magnets. This modularized design not only makes the soft grippers like human fingers to achieve segmental bending, but also reduces the waste caused by local damage. In the soft holder part, we present a bi-directional bending method to automatically adjust the grasping space, and we also establish a mathematical model to describle the relationship between the soft holder's bending angle and the air pressure. Additionally, in order to evaluate the dynamic response and position accuracy of the grasping device, a PID controller is designed for the soft grasping device to track the step, sine, and square wave signals. Finally, the great grasping performance of the fully soft grasping device is verified by experiments.