A Pneumatic Needle Gripper for Handling Shredded Food Products

In recent years, soft robot grippers capable of handling various types of objects including food products have been studied to improve the efficiency of food handling and packaging operations in food factories. However, it has been a challenge for robotic grippers to handle finely shredded food products, such as salad, and grasp a food product in a scenario where there are no gaps among neighboring targets. To this end, this paper presents a pneumatically driven needle gripper that can grasp shredded food products and handle food products through piercing into the target. The gripper is constructed by a soft membrane and six needle-shaped fingers. The gripper is 3D printed using a multi-material 3D printer. By controlling the positive and negative pressures applied on the membrane, the gripper can perform both grasping and piercing operations. Grasping experiments on cabbage salad were conducted and the performance was quantitatively evaluated using the measures of grasped weight and placing appearance.