Geometric design of a kirigami gripper with form-enclosing grasping mode

Although various grasp strategies have been proposed in soft gripper area, form-enclosing grasping mode always plays a marginal role because of the challenges to calculate the deformations of soft materials. In this study, we propose a easy-to-make kirigami gripper and a geometric optimization method to obtain the fingers boundary shape that achieves a complete form-enclosing grasping after bending. We used a FEM model to represent the finger shape and calculated the finger boundary, and then used a iterative method to find the best finger shape that generates the form-enclosing grasping result. The optimization method is based on the minimum energy rule, and has the advantages of being computationally efficient and being universal for optimizing the boundary of gripper with form-enclosing grasping mode. The effectiveness of the proposed method was validated by ANSYS simulation and practical experimental results. Moreover, an objective functions and multiple geometric constraints were derived to quantitatively evaluate the gripper designs.