This article describes a soft robot based onboundary constrained modular subunits. The loop-shaped robot consists of a granule-filled elastic toroidal membrane with a series of modular subunit robots attached to its exterior. The robot can operate both as a soft robot to conform to external objects or navigate through narrow corridors and as a rigid robot by jamming its internal granules using a vacuum. The jammed state is useful for exerting forces on the environment in object manipulation or locomotion tasks. This article describes the robot’s design, object handling capabilities, locomotion, shape formation, and ability to navigate narrow corridors. We also present computationally efficient control methodologies used for self-reconfiguration and target tracking, which enable scaling the number of subunits to create larger systems. The robot’s scalability and the control methodologies are verified through simulation with ProjectChrono, a multibody dynamic simulation platform. All other results are obtained experimentally.

We describe a simple passive universal gripper, consisting of a mass of granular material encased in an elastic membrane. Using a combination of positive and negative pressure, the gripper can rapidly grip and release a wide range of objects that are typically challenging for universal grippers, such as flat objects, soft objects, or objects with complex geometries. The gripper passively conforms to the shape of a target object, then vacuum-hardens to grip it rigidly, later utilizing positive pressure to reverse this transition-releasing the object and returning to a deformable state. We describe the mechanical design and implementation of this gripper and quantify its performance in real-world testing situations. By using both positive and negative pressure, we demonstrate performance increases of up to 85% in reliability, 25% in error tolerance, and the added capability to shoot objects by fast ejection. In addition, multiple objects are gripped and placed at once while maintaining their relative distance and orientation. We conclude by comparing the performance of the proposed gripper with others in the field.

A soft, controllably morphable mobile robot is an ideal platform for traversing complex terrain and navigating small holes. iRobot Corporation and the University of Chicago have made use of a phenomenon known as particle jamming to create such a robot. The robot presented in this work uses jamming skin cells to enable controlled morphing and locomotion.

A soft, mobile, morphing robot is a desirable platform for traversing rough terrain and navigating into small holes. In this work, a new paradigm in soft robots is presented that utilizes jamming of a granular medium. The concept of activators (as opposed to actuators) is presented to jam and unjam cells that then modulate the direction and amount of work done by a single central actuator. A prototype jamming soft robot utilizing JSEL (Jamming Skin Enabled Locomotion) with external power and control is discussed and both morphing results and mobility (rolling) results are presented. Future directions for the design of a soft, hole traversing robot are discussed, as is the role and promises of jamming as an enabling technology for soft robotics.