Hold on Tight

Robotic automation is increasingly being turned to in the consumer goods, logistics, and food industries to meet ever rising demands. Putting robotics to work can not only increase efficiency and reduce costs, but also allows for faster and more precise handling of objects, leading to increased productivity. A key component of a robotic automation system is the end effector, or gripper. In order for objects to be picked up and manipulated in all of the ways that are required to complete a job, appropriate grippers are needed. For this reason, each gripper is typically designed for one very specific purpose, and one purpose only.

Taken together, this means that robotic grippers are not very versatile. A robotic automation system is only useful for one specific type of task, and repurposing it means retooling the entire system. Recent developments in soft gripper technology have proven to be more versatile than their rigid counterparts, but even soft grippers are still inherently limited by their initial design. More versatile grippers may soon be a reality thanks to a team of researchers at the Singapore University of Technology. They have reimagined what end effector design could look like by incorporating compliant structures and pneumatic actuators to achieve highly dynamic grippers suitable for a wide range of grasping tasks.

The so-called reconfigurable workspace soft (RWS) gripper design consists of three pneumatic bending actuators affixed to a soft palm-like base. The actuators can actively morph their shapes and adapt their contact surfaces for many purposes due to some clever design features, including passively retractable nails, bidirectional folding petals, and a flexible palm. These features also give RWS gripper an advantage over other technologies in that it can grip items smaller than the dimensions of its “fingers.” The retractable nails, in particular, allow for grasping of even very thin wires, threads, and needles.

The RWS gripper is able to adjust its workspace volume by up to 397% to adjust to varying types of jobs, ranging from power grasping to scooping tasks. When also considering that the novel actuator design allows for a 56.54% increase in bending curvature over previous devices to enable grasping of a wider range of geometries, RWS gripper looks to be exceedingly versatile.

Experiments were conducted to confirm that the RWS gripper was in fact as versatile under real-world conditions as it was expected to be on paper. The robotic hand was found to be just as effective at grasping a power drill or screwdriver as it was a needle or thread. The system does have its limits, however. It was not successful in picking up a single grain of rice, and a soccer ball also proved to be a bit too much to handle.

Limitations aside, RWS gripper was proven to be quite versatile, and looks to be a promising candidate for situations in which multiple different task-specific grippers would otherwise be needed. That means that robots equipped with RWS grippers can perform unique subtasks in succession, eliminating the need for changing grippers and the accompanying downtime. And for many industries, that could be a major game changer.