Soft Printable Robots With Flexible Metal Endoskeleton

摘要

Recent advancements in soft robotics have seen the rapid development of soft grippers for industrial pick-and-place applications. They are however ill-suited to bear heavy loads due to their compliant nature. Paradoxically, researchers have sought to increase the stiffness of soft grippers to improve loadbearing capabilities. Unfortunately, contemporary soft actuators with variable stiffness are fabricated using manual processes and their performance is subject to an individual's mastery. They are hence not reliable for long-term industrial use. In this paper, we present our work on a 3D-printed metalendoskeleton-reinforced actuator (MERA) for industrial pickand-place applications. We also highlight the fabrication processes needed to recreate it repetitively. Using stainless steel splints (SSS), we demonstrate that MERA is able to modulate its stiffness at selective junctures for stable and effective grasping. We also describe our design rationale with a qualitative mathematical model and validate its performance quantitatively using a finite element model, which is further investigated in the following fatigue test. In our experiments, the MERA equipped with SSS is able to output a peak tip force of 8N, which is a 291% increase compared to the one without metallic reinforcement. In addition, an increase of 76.5% in gripping load and a maximum holding force per actuator of 13.8N are realized through the stiffness tuning of a MERA-Gripper. Despite significantly improving loadbearing capabilities, the actuator manages to retain an overall low profile with a weight of 82g. Finally, we adapted the MERA into a reconfigurable gripper and tested its grasping capabilities on objects of various shapes, sizes, and weights.