Layer jamming skin‐based bionic webbed foot soft gripper with variable stiffness and envelopment

Inspired by webbed feet, a bionic webbed foot soft gripper with variable stiffness was designed by integrating a pneumatic networks actuator with layer jamming skin. Layer jamming skin as the key component of bionic webbed foot soft gripper, its design and fabrication process were described. An experimental platform combining stretch/bend control was established to analyze the impact of activated negative pressure, different materials and shapes jamming units, and the number of jamming layers on the stiffness of the layer jamming skin. The layer jamming skin conforms to the characteristics of variable stiffness by evaluating the experimental and numerical results of the layer jamming skin under external loading. The curling and adaptability test demonstrated the layer jamming skin's adaptability and flexibility to various shapes and sizes of caught objects. The variable stiffness, adaptability, and gripping force of the bionic webbed foot soft gripper during object grasping were assessed through gripping experiments. This work presents an enveloping gripper with variable stiffness, high adaptability, and strong grasping force.