Jamming on Soft Robotics and Engineering Collaborations

Collaboration between engineering and the other sciences is critical to innovation.

Nowhere is this more evident than at institutions like the Materials Research Science and Engineering Centre (MRSEC) at the University of Chicago.  One of many National Science Foundation (NSF) funded research groups, the MRSEC brings together engineers, scientists and researchers to develop next-generation materials and use them in creative ways to solve problems.

One of the projects in development is a unique design for robotic grippers that are able to pick up objects of any shape by combining the phenomenon of jamming with soft robotics. To learn about the development of this gripper design, ENGINEERING.com spoke to graduate student Nicole James from the University of Chicago, at the USA Science and Engineering Festival.



James explained that ‘jamming’ is a term used to describe a phase transition characteristic of granular, fluid-like materials, where the material changes from a fluid-like state to a solid-like state. In the case of UChicago’s design, the transition is accomplished by removing the air from a balloon full of fine sand.

Unlike most phase transitions, such as ice melting into water, “the control parameter here isn’t temperature. I didn’t have to heat the system up, or cool it down. All I did was limit how much space there was between the particles,” James said.  This means it’s easy to “un-jam” the material simply by letting air back into the balloon.

So how does this phenomenon apply to robotics?

“A really hard problem in robotics is, ‘How do I grab something if I don’t know beforehand what shape it’s going to be?’” James explained. Most current gripping robots have a robot hand, with robot fingers, and every joint that needs to move has a motor and sensors connected to a computer that tells it how to pick something up.

Building a soft robotic gripper has several advantages over these traditional configurations. Chief among them is the ability to pick up irregularly shaped objects easily, without the risk of over-compression that could cause damage.

“In robotics, it’s very difficult to handle fragile objects, because robots often over-compress, and they snap pencils, they fracture eggs,” James said. “They can break things easily because they’re very strong.”

Soft robotic gripper conforming around an object to pick it up. (Image courtesy of Jaeger Lab/University of Chicago.)


“This [soft gripper] is never compressing,” she explained.  In its liquid-like state, the gripper conforms to the shape of the object, and when the air is pumped out, the granular material jams, conforming to and thereby holding an object without excess pressure. This means that the robot could pick up a variety of items easily, without the need for specialized fingers or programming.

The soft jamming robotic gripper is capable of picking up irregularly shaped objects easily. (Image courtesy of Jaeger Lab/University of Chicago.)

James offered an example of using a jamming soft robotic gripper for search and rescue. “Say a train derails, and you want to send a robot in to move away all that debris.  That’s a really hard problem, because you have no way of anticipating the shapes and orientations of the objects.  With these soft jamming robotics, you don’t need to.”

It all comes back to collaboration, James asserted.  “My boss, Heinrich Jaeger, is a granular physicist, he’s not a roboticist.  This isn’t a thing where he set out trying to create a universal gripper for a robot. He set out trying to figure out why grains flow in some situations and don’t flow in others.”

“But through collaboration with robotics companies, he found out ‘Oh, you have this really hard problem, and we have this solution’.  But that’s also something a roboticist might not necessarily have thought of, when they probably never heard of jamming.  So, this is a situation where you really need a collaborative, interdisciplinary approach.”

As for why James and the University of Chicago team came to the USA Science and Engineering Festival, it’s because they see the importance of showing the younger generation how engineering and science can work together to produce innovative solutions and technologies.

“We had a very traditional structure, of ‘I am a chemist, she is a physicist’ and I work on chemistry and she works on physics, and that’s not how a lot of important research happens anymore. It happens in collaboration with a lot of people.  I think now is a great time to start talking to kids about working together with people from different backgrounds, and different experiences, and trying to solve difficult problems together.”

To learn more about Jamming Soft Robotics, you can watch the video above or visit the University of Chicago’s Jaeger Lab project website.


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