Development of a Hybrid Gripper with Soft Material and Rigid Structures

For decades, various robotic grippers have been developed due to its necessity for the robotic manipulators. In case of the conventional robotic grippers with rigid components, an underactuated mechanism was required to satisfy gripping motion. Recently, soft grippers have been studied actively, which have realize bending motion with a simple morphological structure itself and inherent compliance to the environment. In this field of study, it has been rarely investigated to improve the fingertip force and actuation speed with specified design parameters. Thus, in this study, a hybrid gripper, which consists of both soft and rigid components, was suggested based on the key design principles: 1) the ratio of rigid parts against the soft chamber, 2) the cross-sectional shape of the chamber. The suggested principles were verified using the finite element methods (FEMs). As a result, the improved performance of the hybrid gripper was verified in terms of the fingertip force and the actuation speed, compared with the performance of the previously developed soft pneumatic actuators (SPAs). As an application, the three-fingered gripper was manufactured and tested by grasping different types of objects.