Robots have become shockingly advanced in the last few years – just take a look at a recent video from Boston Dynamics if you doubt that. However, robots are still pretty bad at one vital task: picking up irregularly sized objects. The solution may be so-called “soft robotics,” which focuses on the use of flexible, compliant materials rather than rigid metal and plastic. A new project in this field by Harvard scientists consists of a tangle of tentacles. Thanks to its monstrous appearance, the tentacle grip can pick up almost any small object without damaging it.
The robot was developed by researchers at Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS). The problem with robotic grippers is twofold. Most of the effective ones are rigid, making it difficult to lift irregular or breakable objects. They also require sophisticated, embedded sensors and control mechanisms with feedback and machine learning algorithms. There’s just a lot that can go wrong, all to make something that even a toddler can do without much trouble. The tentacle gripper is designed to mimic the way jellyfish capture stunned prey. Although one or two of the tentacles aren’t enough to pick up even the smallest objects, working together gives the robot plenty of redundancy and lifting power.
Unlike most graspers, tentacles do not require sensing, planning, or feedback control. They are pneumatically actuated—when off, they hang free, allowing the operator to swing them over the target. When activated, the spindle-shaped rubber tubes contract. As you can see in the video, the tentacles wrap tightly around the target as they move.
“Entanglement allows each highly compatible strand to conform locally to the target object, resulting in a secure but gentle topological grip that is relatively independent of the details of the nature of the contact,” said L. Mahadevan, Professor of Applied Mathematics at SEAS. That’s a fancy way of saying that the tentacles can grab just about anything. The team tested the catcher on a variety of objects, such as the houseplant seen above. It can also pick up soft fruits and vegetables without crushing them.
The SEAS team sees many potential applications for the tentacle robot, such as agriculture, marine biology and warehouse management. The research, funded by the National Science Foundation, is published in the Proceedings of the National Academy of Sciences.