Fully 3D-printed gripper jaw with embedded sensitive sensor structures for robotic applications

In this contribution, we present a novel, fully 3D-printed sensitive gripper jaw for high gripping forces up to 40 N. The fabrication process is based on fused layer manufacturing, in which two different materials are sequentially extruded. The gripper jaw is based on a sensor design with multiple-stacked bending beams and four sensor elements, each printed directly into one of the upper and lower bending beams. The research focuses on the sensor design of the gripper jaw, the mathematical description and simulation, the fabrication process, the electrical characterization of the sensor material, and the sensitivity behavior of the gripper jaw in terms of zero-point deviation, characteristic value deviation, linearity behavior, repeatability, and viscoelastic behavior. In addition, the gripper jaw is compared with a similarly manufactured gripper jaw with conventionally attached strain gauges, as well as with other comparable fully 3D-printed sensors to classify the sensor quality. The results demonstrate that the fully 3D-printed gripper jaw is partially suitable for sensitive and fragile components. The gripper jaw is well suited for detecting the gripping state (part gripped / not gripped). • Fully 3D-printed functional gripper jaw. • Structural and sensing functions integrated in a single additive process. • Simulation and analytical model are consistent with experimental results. • Sensor shows a high gauge factor of 3.8 compared to conventional metals. • High gripping force of 40 N achieved.