Origami soft gripper brings light touch to heavy loads

Engineers at MIT’s Computer Science & Artificial Intelligence Laboratory have used an origami design to create a vacuum-powered soft gripper capable of lifting objects more than 100 times its weight.

Soft robotic grippers are widely used across industry to move everything from fruit to delicate glassware, but the strength with which they can grasp objects is usually limited. Employing a ‘magic ball’ origami design, the MIT team created a soft gripper that’s capable of lifting much heavier items.

The magic ball structure features folds that allow it to morph from a spherical shape into a cylindrical form. Using a hemisphere with this origami design, the engineers created skeletons for the gripper, which were covered with a variety of airtight flexible materials. When vacuum pressure is applied, the hemisphere compacts into a cylinder, closing tightly around target objects. The research is published on MIT’s website and will be presented at the 2019 IEEE International Conference on Robotics and Automation in May.

“Soft robotics has yielded numerous examples of soft grippers that utilise compliance to achieve impressive grasping performances with great simplicity, adaptability, and robustness,” according to the paper’s abstract. “Designing soft grippers with substantial grasping strength while remaining compliant and gentle is one of the most important challenges in this field.

Origami gripper (Pic: Jason Dorfman- MIT CSAIL)

“In this paper, we present a light-weight, vacuum-driven soft robotic gripper made of an origami ‘magic-ball’ and a flexible thin membrane. We also describe the design and fabrication method to rapidly manufacture the gripper with different combinations of low-cost materials for diverse applications.”

According to the paper, three different prototypes were created. Two featured magic ball skeletons of 3D printed silicone rubber covered with latex balloon skins, while the third used a magic ball with a self-folding PET structure encased in a TPU (thermoplastic polyurethane)-coated nylon fabric. A video of the grippers in action shows them grasping an array of different objects, including fruit, toys, smartphones and tools, as well as significantly heavier items such a power drill and a small quadcopter. The researchers believe the gripper’s performance could be improved further by incorporating materials such as anti-slip tape or gecko-inspired adhesives, or with the addition of suction cups into the skin.