September 14, 2015      

Researchers at Worcester Polytechnic Institute have won federal grants for two projects to continue development of so-called soft robotics, which could be useful in medicine, manufacturing, and disaster response.

The National Science Foundation awarded Dmitry Berenson, an assistant professor of computer science, a three-year grant of $322,319 to study “human-supervised manipulation of deformable objects.” The NSF also awarded Berenson a two-year grant of $247,355 for research into “fundamental algorithms for design, control, and motion planning of soft manipulators.”

What’s the difference between segmented joints and soft robotics? “We typically use various silicone rubber formulations,” replied Cagdas Onal, an assistant professor of mechanical engineering at WPI. “While soft robotics doesn’t really prevent one from using a segmented architecture — for control purposes — the main difference is a continuously deformable body. A segmented robot made of rigid materials would make discrete angles, which may jam inside small, complicated tunnels or cluttered environments. Plus, they may cause damage or injury.”

“The most dangerous part of working with a rigid robot is actually not the risk of being hit by the robot, as most people believe. This risk can be limited by simply having the robot move slower,” said Berenson. “What can cause far more severe injury is if the human is pinched or crushed between the robot’s joints. … For soft robots, we expect that this risk will be substantially less, as the robot can [conform] to the shape of the human.”

Autonomous and adaptable robots
“Deformable objects” are “an under-explored area of robotics, and through these grants, we’re aiming to learn more about how soft robots and materials could be used in a variety of applications,” said Berenson. The National Robotics Initiative grant to WPI and Case Western Reserve University in Cleveland is intended to develop intelligent and dexterous surgical assistants.

Cagdas Onal and Dmitry Berenson are teaming up on soft robotics research at WPI.

Professors Onal and Berenson in the Soft Robotics Laboratory in the Higgins Laboratory building at WPI.

Unlike conventional endoscopes or surgical tools, which require precise human control, Berenson’s team is working on automated tools that can more easily adapt to the shapes of organs and tissues inside the body.

“However, a human will always be in the loop, and they will be able to choose to stop the system or take control at any time,” he said. “They will also be able to change the system’s strategy to perform a task in a certain desirable way if the system chooses to do it a different way.”

“The central challenge in this work is to control the motion of the robot or flexible object in a way that takes into account its flexibility and predicts what kind of changes there will be in the environment as a result of the motion,” Berenson explained to Robotics Business Review. “Understanding how to work with flexible objects in a general-purpose way is a huge frontier in robotics.”

EAGER development
The Early Concept Grant for Exploratory Research (EAGER) into controls and soft manipulators will help WPI with research into robots that can maneuver through confined spaces for tasks such as search-and-rescue missions.

For instance, a robot similar to an elephant trunk could be strong enough to lift rubble, and one modeled on an octopus tentacle could help find a person, said Onal, who is a co-investigator on the grant. However, much research needs to be done before applications can be defined.

“[Our] focus is on the fundamental design, control, and motion-planning challenges that need to be solved before we can utilize soft robotic manipulator arms in real-world scenarios,” Onal said. “Once these problems are addressed in this project, we can envision a broad range of applications, such as robots performing alone autonomously, in collaboration with human workers, or under teleoperation.”

Roboticists at WPI and elsewhere have turned their attention to biomimicry, or robotics designs inspired by animal adaptations, for locomotion and gripping. Robots that can climb vertical surfaces, squeeze through narrow spaces, or gently handle varied and fragile items could be more helpful than simpler mechanical or still-clumsy humanoid robots.

“A soft arm is a potential solution to many challenges we face in human-centric manipulation tasks,” said Onal, who added that soft robots could prove useful working alongside humans in factories.

“We are really seeking to lay the fundamental groundwork here, and there are many applications that can result,” Berenson said. “We do envision that, even in teleoperation modes, the robot will have some autonomy — i.e., you would not be commanding the joint angles of the robot directly, but rather giving it a command like, ‘Reach behind that rock.'”

More on Healthcare and Soft Robotics: