Actuatorless Caging Gripper with Interlinked Fingers Driven by Contact Force with the Ground

Grippers are extremely important in robotics. Conventional grippers are composed of rigid components, but soft grippers made of soft materials have also gained considerable attention. Most grippers require actuators such as electrical motors and pneumatic systems for driving; however, these actuators increase the weight and complicate gripper wiring. Although grippers operating without actuators have been developed, they can only be used in certain environments. In this study, we propose a novel actuatorless gripper driven by the contact force with the ground. The proposed interlinking mechanism that connects the fingers enables the gripper to be used even in sloped environments. We experimentally confirmed that this mechanism expands the range of environments in which grasping is possible and improves the grasping success rate. Moreover, the proposed gripper could grasp objects that cannot be grasped using conventional actuatorless grippers, such as soft, unstable, and low-height objects. Additionally, we developed a design model for the proposed gripper, which was verified experimentally in terms of deformation of the fabricated gripper.