Origami patterns have provided the inspiration for a new type of gentle gripper with possible applications in agricultural robotics.
Korean researchers developed the concept based on the Yoshimura pattern, a triangular mesh design which buckles easily. In this case, the idea was for the gripper to softly envelop its target, rather than grasp it. After optimising the pattern for their needs, they 3D-printed the design on fabric and attached magnets to its two entrances to increase the sealing force when it wraps an object.
In addition to the gripper itself, the team designed a frame and legs to mount it on and attached a motor. The opening and closing action were controlled by pulling and releasing an attached wire.
In agriculture, such a gripper could be used as part of fruit-picking robots, where sensitive handling is essential. With such uses in mind, the team tested its ability to safely pick up eggs, harvest cherry tomatoes and grasp a silicon model jellyfish in water. In all cases, the gripper successfully enveloped the object with no crush marks or other damage.
Multiple advantages
There has been considerable interest in developing soft grippers for robotics in recent years. as part of the push towards greater automation across a number of industries, but according to the researchers, their design overcomes limitations seen in those currently available.
“Existing soft grippers use large actuators or operate at high voltages, which limits their use. However, our origami-based soft encapsulating gripper can be operated with a single motor due to the programmed folding and unfolding of the 3D origami structure,” the scientists wrote in the journal Robotics.
“With this simple structure, our origami-based soft encapsulating gripper exhibited three demonstrations of encapsulating brittle, fragile, and soft objects.”
As well as this simpler operation, another advantage is that the gripper’s size and shape can easily be changed by adjusting geometric parameters in the origami pattern. These qualities lend the design to applications in both farming and engineering, they concluded.
