Trunk-inspired robot gripper can pinch and grab objects small and large
The flexible "fingers" at the tip of an elephant's trunk have provided the inspiration for a versatile robotic gripper capable of picking up and holding onto a variety of objects both large and small – from an acupuncture needle to a thin metal ruler to a large packaging box.
A bit like a huge slinky covered in tough skin and jam-packed with muscles and nerves, an elephant's trunk has many uses – packing a powerful sense of smell, able to suck up water or dirt, and get to grips with different-shaped objects. It's been a source of inspiration in robotics for a number of years, having obvious applications in pick-and-place operations, and the latest development from researchers at the Korea Institute of Machinery and Materials (KIMM) looks to be one of the most capable yet.
Pitched as the "world's first elephant-trunk-mimetic robot hand," and combining the capabilities of a claw-type gripper with a suction type grabber, the device is able to pinch and grasp objects via soft structures at the tip.
Wires driven by a pneumatic cylinder are fed across the center of this soft structure and alter the gripper's shape when activated, allowing its claws to partly fold in on themselves to pinch and grab objects, while embedded micro-channels create a vacuum seal to increase the gripping force as necessary.
This essentially means that the gripper can pick up objects of different shapes, sizes and weights – which the KIMM team demonstrated by grabbing a 0.25-mm-diameter needle plus a packing box that was 10 times its size. Other tasks included gift-wrapping a doll, plonking candles on a cake before lighting them using matches and even engaging in a spot of flower arranging.
"After contacting the soft gripper to the floor and then creating a vacuum while conducting a pinching motion, the gripper can grip objects as if you were strongly pinching the floor with your fingers," said the team's Dr. Sung-hyuk Song. "In this way, even very thin objects can be easily gripped and be lifted from the floor."
The researchers reckon that the system operates without needing a complex sensors or controls, and the soft gripper shouldn't pose an injury risk when operated around people. As such, future applications for the technology include assembly bots on production lines and service robots around the home.
"Not only can it handle objects of various sizes, from fine parts to boxes, without complex mechanical structures or sensors, but also it can be handled easily, which means it can be applied to various industries as well as daily life," said Dr. Chanhun Park, Director of the AI Robot Research Division. "I expect it to be of great help to the development of service robots in daily life and companies that produce a variety of different objects."