A Soft Gripper with Granular Jamming and Electroadhesive Properties

In recent years, there has been a growing interest in the development of universal soft grippers that can handle objects of varying form factors (including flat objects), surface conditions (including moistened or oily objects), and mechanical properties (deformable and fragile). Yet, there is no single gripper that can gently grip objects with such a wide range of properties. Herein, a soft gripper that combines granular jamming (GJ) and electroadhesion (EA) to gently grasp and release a large set of diverse objects is presented. The gripper can operate in GJ mode only, in EA mode only, or in a combination mode that simultaneously activates GJ and EA. In GJ mode, the gripper can grasp objects with different surface properties, lift objects 38 times its own weight using negative pressure, and release objects by applying positive pressure, but has difficulty in handling flat and fragile objects. In EA mode, the gripper can manipulate flat and fragile objects but encounters difficulties with different surface properties such as oily or moisture. In the combination mode, the gripper can generate grasping forces up to 35% higher than in the GJ mode for all object sizes and certain shapes such as a cylinder.