Shape-Forming Donut-Shaped Soft Gripper

In this paper, the design and demonstration of a shape-forming soft gripper with a donut body is explored. The vacuum-powered donut soft gripper has a 2.50 mm thick silicone membrane and is filled with 7.50 g of polyester fiberfill to allow shape-forming around the target object. Unlike other vacuum-powered soft grippers where the interior materials are mostly hard, our donut soft robot is inspired by a vacuum bedding storage bag, which provides a soft touch to the target object while allowing the gripper to form the required shape around the target object when actuated. Polyester fiberfill contains excelling flexibility and resiliency, it can easily deform based on its surroundings but also return to its original shape quickly when the external force is removed, making it a promising candidate for a shape forming soft gripper. The donut soft gripper's physical attributes include four indents at the base, with an outer diameter of 84.62 mm, inner diameter of 12.92 mm, and thickness of 40.00 mm. With the donut robot filled with polyester fiberfill, the donut parameters are optimized for bearing weight and has the best shape forming ability. The donut soft robot is capable of securely holding objects of different shapes, including a miniature teapot, a polygon ball, a Lego block, a spice bottle, as well as soft objects like a tomato.