Soft Grasping Delicate Parts by Robotic Effectors

This paper deals with the problem of reliable grasp of delicate objects by robotic effectors when handling or any physical interaction with the environment. The principal condition for such a task is to prevent any damage to the object by contact forces. The brief comparison of hard and soft contacts/grasps with regard to the load capacity of a gripper is discussed. In the case when contact forces are limited a more reliable grasp be reached if all contacts between grasp elements/fingers and object surface are soft. This condition should be respected in the design of effectors for manipulation with biomaterials or living organisms e.g. in medical operations, for handling fragile objects in optoelectronics, or in agriculture for harvesting soft fruits or plants. The grippers for these purposes are usually task-oriented tools and should be designed as relatively simple devices. An illustrative example of the gripper with an artificial “soft contact surface” is shown.