Soft Gripper with EGaIn Soft Sensor for Detecting Grasp Status

With the Fourth Industrial Revolution, many factories aim for efficient mass production, and robots are being used to reduce human workloads. In recent years, the field of gripper robots with a soft structure that can grip and move objects without damaging them has attracted considerable attention. This paper proposes a variable-stiffness soft gripper, based on previous designs, with an added silicone coating for increased friction and an EGaIn soft sensor for monitoring grip forces. The variable-stiffness structure used in this study was constructed by connecting soft structures to rigid structures and using tendons fixed to the rigid structures. Furthermore, a more responsive EGaIn soft sensor compared to existing sensors was designed by adding bumps to the path traced by the alloy. After selecting the appropriate fingertip shape, changes in the output of the EGaIn soft sensor corresponding to the object held by the soft gripper were observed, confirming that the strength of the device could be changed according to the intended purpose.