Granular jamming based gripper for heavy objects

Moving of heavy objects with overhead cranes requires the operator to fasten the object to the hook via ropes or chains. This is a time consuming process, which would be avoided with universal grippers, that can lift objects regardless of shape. In this paper the scalability of granular jamming grippers for crane applications by designing and building a large scale grippers using simple materials and different granular materials has been studied. Objects of different shapes and sizes were successfully lifted with certain gripper configurations. The results showed that grain size and grain compressibility both affect the performance of the gripper. It was shown that in order to efficiently lift heavy objects with granular jamming the granular material has to not only be able to compress sufficiently in the vacuum but also have large enough stiffness. With this setup, gripper based on the granular jamming was able to lift objects with various shapes and weights up to 120 kg.