Development of a Suction-type Soft Robotic Gripper with Variable Diameter for Increasing the Versatility

Soft robots present advantages such as flexibility and versatility, potentially addressing challenges that rigid robots face in tasks like crop harvesting, transportation, and processing. Among these, suction-type robot grippers, known for their simple grasping motion and high speed, are widely utilized both in research and industrial production lines compared to other types of robotic hands. However, a key limitation exists when attempting to grasp objects smaller than the suction cup’s outer diameter or when the pad cannot fully seal the surface. In manufacturing settings, where object specifications are predefined, the appropriate suction cup size can be selected in advance. In everyday scenarios, however, where objects vary in shape and size, it is impractical to choose a single suction hand that suits all situations. To address this issue, a suction-based robotic gripper has been developed, featuring the ability to actively adjust the suction cup’s diameter to better match the surface being grasped, thereby enhancing versatility. This paper presents the concept, design, fabrication process, and preliminary experimental results that demonstrate the effectiveness of the proposed device in various grasping scenarios. The findings of this research may contribute to the development of suction hands/grippers capable of actively altering their morphology to achieve optimal grasping for different objects.