This Vine-Like Grasper Gives Robots a Secure Yet Gentle Touch

Researchers from the Massachusetts Institute of Technology (MIT), Stanford University, and the University of Florida have developed a soft robotic gripper well-suited to handling delicate yet heavy objects — taking inspiration from strangling vines.

"Heavy but fragile objects, such as a human body, are difficult to grasp with the robotic hands that are available today," says co-author Harry Asada, Ford Professor of Engineering at MIT, of the team's work. "We have developed a vine-like, growing robot gripper that can wrap around an object and suspend it gently and securely."

"Transferring a person out of bed is one of the most physically strenuous tasks that a caregiver carries out," adds first author Kentaro Barhydt of the target use-case for the new gripper. "This kind of robot can help relieve the caretaker, and can be gentler and more comfortable for the patient."

The gripper developed by the team is designed to mimic how vines reach out and grab onto surfaces — and, in the case of strangling vines, other plants. It's made from a pressurized box from which vine-like tubes inflate, twisting and coiling around the target object before returning to the box and getting clamped in place — changing from an open-loop to a closed-loop sling-ling grabber.

"People might assume that in order to grab something, you just reach out and grab it," Barhydt explains. "But there are different stages, such as positioning and holding. By transforming between open and closed loops, we can achieve new levels of performance by leveraging the advantages of both forms for their respective stages."

Testing showed the gripper was able to grasp and lift a range of heavy and fragile objects, including bed-bound patients, and that it could push through clutter and tight gaps to reach its target. While healthcare is at the forefront of the team's focus, it's not alone: the researchers say that the same gripper type could be used for everything from agricultural harvesting to unloading heavy cargo.

"I am very excited about future work to use robots like these for physically assisting people with mobility challenges," says co-author Allison Okamura, the Richard W. Weiland Professor of Engineering at Stanford University. "Soft robots can be relatively safe, low-cost, and optimally designed for specific human needs, in contrast to other approaches like humanoid robots."

The team's work has been published under open-access terms in the journal Science Advances.