A Physically Intelligent, Multimodal Universal Soft Gripper Using Granular Materials

Abstract

The variety and unpredictability of objects make the development of universal grippers an imperative in the field of robotics. However, most existing universal grippers either adopt a single gripping mode with limited gripping capabilities, or combine different gripping mechanisms to achieve a non-single gripping mode, which inevitably increases the complexity of structure and control. Through a homogeneous design without introducing any additional mechanism, a physically intelligent, multimodal universal soft gripper using granular materials is demonstrated that enables four different ready-to-use gripping modes. These four gripping modes are encoded in the gripper structure by designing the gripper with three internal axisymmetric, independently controllable chambers. Continuing the traditional jamming gripping mode, this design can also realize two bionic, complementary vacuum gripping modes. These vacuum modes enable to grip planar objects weighing over 265 N or as small as 4.5% of the gripper diameter, as well as extremely fragile objects such as half an eggshell. Moreover, the gripper can realize a vacuum-jamming integrated grasping mode, allowing for a grasping force of more than 300 N.