A Soft Gripper with Granular Jamming and Electroadhesive Properties    

Abstract

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 condition (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. In this paper, we present a soft gripper that combines granular jamming (GJ) and electroadhesion (EA) to gently grasp and release a large set of diverse objects. 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 moistened. In the combination mode, the gripper can generates grasping forces up to 35% higher than in the GJ mode for all object sizes and certain shapes such as a cylinder.

A Stretchable Jamming Gripper Grasping Flat Plates

“…To address the inability to grip flat objects such as A4 paper, deformable objects such as fabric, extreme environments and objects with a larger effective area than a granular bag, researchers have combined different gripping technologies to complement each other's limitations to create this versatile gripper. Piskarev, Y et al combined two different technologies: granular jamming (GJ) to control stiffness and electroadhesion (EA) to control adhesion, which was demonstrated to manipulate objects of various shapes [12]. Song, S. et al proposed GeckoGripper, based on the controllable adhesion mechanism of gecko-inspired microfiber adhesives and jamming gripper, to grip wide variety of 3D or fragile parts, like steel balls on the order of millimeter [13].…”

Constrained Trajectory Optimization and Force Control for UAVs with Universal Jamming Grippers

“…Unlike many other soft grippers, the UG is specially crafted to engage with a wide array of object geometries 45,46 and delicate manipulations 47 , showcasing enhanced adaptability in handling various manipulation tasks. Its symmetric design and omnidirectional grasping capabilities sidestep the complexities of intricate orientation strategies that many other grippers grapple with [48][49][50] . Moreover, its lightweight composition, featuring a membrane filled with granular material, contrasts with the more substantial conventional finger-like grippers 51 .…”