An origami-inspired monolithic soft gripper based on geometric design method

Soft end-effectors have great potential on object manipulation. The top-down approach using origami spring structure to create robots is increasingly spreading, with capabilities of simplification and acceleration for the design and fabrication procedure at low cost. In this study, a synergy is achieved through combination of origami pattern with 3D-printed soft robotics. In this letter, we have developed a monolithic soft gripper which deforms based on the constrained configuration space induced by origami structure. A geometric design method is proposed to model the hyperelastic deformation of elastomer material and the trajectory of fingertips is iteratively computed with residuals in geometric objective as approximated deformation using Newton's minimization method. Two characteristic tests quantifying the gripping capability of the soft gripper and a grasping demonstration of daily objects are conducted to show its practical performance. The experimental results indicate the linear relationship between input and output variables with a scale factor of 3.79 on the displacement amplification, showing that the required control scheme could be simple. Besides, handling a range of target objects presents the versatility and universality of the manipulator in daily life.