South Korean researchers were inspired by how fast chameleons can accelerate their tongues to snatch insects, despite how slow they move. A team from Seoul National University of Science & Technology (SeoulTech) developed a robotic tongue that mirrors this remarkable skill by springing forward to grasp nearby objects at astounding speeds.
The researchers envision this new robotic tongue, dubbed Snatcher, to be used by robots and drones that need to grab items without getting too near them. “For example, a quadrotor with this manipulator will be able to snatch distant targets, instead of hovering and picking up,” explains a researcher at SeoulTech, Gwang-Pil Jung, who co-designed the device.
How did Jung and his colleague Dong-Jun Lee build Snatcher? They started by developing a spring-like device that’s controlled by a combination of an active clutch and a single series elastic actuator. A steel tapeline, powered by a wind-up spring, passes through two geared feeders. The clutch allows the single spring to unwind in one direction to drive the shooting and the retracting, by turning a geared wheel between driving the backward feeder and the forward feeder.
The final result is a lightweight device that packs chameleon-tongue snatching abilities into a portable form, weighing under 120 grams with a total size of 12 x 8.5 x 8.5 centimeters. Still, it’s able to quickly retrieve items up to 30 grams from 80 centimeters away within 600 milliseconds.
Jung said:
Our final goal is to install the Snatcher to a commercial drone and achieve meaningful work, such as grasping packages.
There is still room for improvement including, powering the actuation system more efficiently and replacing the simple hook that’s currently used to grasp objects with a chameleon tongue-like gripper. “To solve this issue, we are finding materials having high energy density, and we are planning to make a bi-stable gripper to passively grasp a target object as soon as the gripper contacts the object,” Jung clarifies.
The duo published the full description of Snatcher in IEEE Robotics and Automation Letters on July 21, 2020.
