Video: Soft robot can lift objects 100 times its weightPeter Brown | March 15, 2019
The growth of soft robotics has accelerated in recent years. New developments in the area could include robots that can pick up objects and move them, or industrial collaboration robots to work alongside humans.
Rigid robots tend to work only in environments with predefined shapes and locations and cannot cope with uncertainties in placement or form. Soft robots, typically made of materials such as rubber, can solve this problem with artificial fingers that allow them to pick up smaller objects such as grapes. However, they are unable to typically handle large or heavy items.
Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have developed a new type of robot that is both soft and strong. The robot has a cone-shaped origami structure that collapses in on objects — like a Venus flytrap — and picks up items as much as 100 times its weight.
MIT said the soft robot can also pick up a wide range of objects such as soup cans, hammers, wine glasses, drones or a broccoli floret.
“Previous approaches to the packing problem could only handle very limited classes of objects — objects that are very light or objects that conform to shapes such as boxes and cylinders, but with the Magic Ball gripper system we’ve shown that we can do pick-and-place tasks for a large variety of items ranging from wine bottles to broccoli, grapes and eggs,” said Daniela Rus, director of MIT’s CSAIL. “In other words, objects that are heavy and objects that are light. Objects that are delicate, or sturdy, or that have regular or free form shapes.”
The gripper is cone-shaped, hollow and vacuum-powered and envelops an entire object as it picks it up. The gripper has three parts: the origami-based skeleton structure, the airtight skin of the structure and the connector. The gripper is made of rubber and a special heat-shrinking plastic that self-folds at high temperatures.
MIT tested the gripper’s strength on different objects and found it could grasp and lift objects 70% of its diameter, so it could pick up and hold a variety of soft foods without causing damage. It could also pick up bottles weighing more than 4 lbs.
“Companies like Amazon and JD want to be able to pick up a wider array of delicate or irregular-shaped objects, but can’t with finger-based and suction-cup grippers,” said Shuguang Li, a joint postdoc at MIT CSAIL and Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS). “Suction-cups can’t pick up anything with holes — and they’d need something much stronger than a soft-finger-based gripper.”
While the robot works best with cylindrical objects, MIT said it could someday make it applicable for production lines in factories. However, it has difficulty grasping things that are flat such as a book or sandwich.
The next steps include solving the problem of angle and orientation by adding computer vision that would let the gripper “see” and make it possible to grasp specific parts of objects.