A Soft Needle Gripper Capable of Grasping and Piercing for Handling Food Materials

Automation in the food industry is not as developed as in the automotive industry because of difficulties in handling food products with large variations in shape, size, and mechanical properties. In this paper, a pneumatic-driven soft needle gripper is proposed for handling food materials. It was constructed using a soft membrane and multiple rigid needle-like fingers. It can work under two operational modes: grasping and piercing. The grasping mode can be used to grasp shredded and chopped food materials. The piercing mode is for handling food products when only the top surface of the food product is available for handling. The needle gripper is fabricated using a multi-material 3D printer. Experimental tests on various food materials are conducted to validate grasping and piercing operations. The results of grasping tests suggest that the needle gripper can successfully grasp shredded and chopped food materials. A quantitative analysis shows that the relative standard deviation of the grasped food weight was within 20%. Although the results of piercing tests validate that the needle gripper can successfully handle various food materials, releasing the food materials involves certain difficulties.