KIMM Builds First Robotic Hand Capable of Gripping Needles

A newly built gripper robot can grasp all kinds of objects, ranging from very fine or thin items like sewing needles and acupuncture needles to large items like boxes.

The Korea Institute of Machinery and Materials (KIMM), an institution under the authority of the Ministry of Science and ICT, reports that it has built the world’s first gripper capable of all gripping movements, drawing inspiration from elephant trunks.

In particular, the gripper imitates how elephants pick up small items by pinching them with the tip of their trunks or gripping large items by sucking in the air strongly via their trunks.

The research team, guided by Dr. Sung-Hyuk Song, a Senior Scientist at the Department of Robotics and Mechatronics in the KIMM AI Robot Research Division, designed and built the gripper that mimicked a trunk. This gripper can grip objects with a pinch-suction fusion mechanism using its stretchable-thin wall, soft structure, and wires that enable the gripper to alter its shape.

The researchers anticipate that this new technology will be used in a range of fields, as it can efficiently carry different sizes of objects and grip and assemble items in a stable manner without the need for any complex sensors or mechanical devices.

The gripper’s soft structure has several micro-channels that form a vacuum inside, helping it adhere to an object. Since each of these micro-channels is flexible, it can alter its shape to suit the objects it encounters. Therefore, the soft structure itself works as a suction gripper by forming an adhesive force on the surface of objects.

Furthermore, by pulling the wires that regulate the gripper’s shape, positioned in the center of the soft structure, the gripper can fold in half on its own, which enables it to be used like a claw gripper, pinching and clutching objects. When employed in this manner, the stretchable-thin wall situated outside the gripper wraps around and encloses the target object.

The gripping force can be significantly raised as required by forming a vacuum within the gripper after pinching and sealing the object. Over recent years, the grippers have been designed individually as suction or claw types. The claw-type grippers cannot grasp items bigger than the maximum size at which the claw can be stretched out.

In the meantime, suction-type grippers can grip items of different sizes but find it difficult to grip extremely thin objects such as thread or needles or objects such as sponges or cloths that air can travel through.

The newly developed KIMM gripper can grasp objects of different sizes and materials by concurrently applying the claw-type gripping mechanism and the suction-type gripping mechanism.

It can grasp small items, like acupuncture needles measuring 0.25 mm in diameter from the floor, which are much smaller than one hundredth the size of the gripper. It can also grip large-size items like boxes that are ten times larger than itself. 

Moreover, this gripper can pinch and grip several objects in the claw gripping mode by switching on and off the pneumatic cylinder that moves the shape-altering wires without any complex controls or sensors.

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. In this way, even very thin objects can be easily gripped and be lifted from the floor.

Dr. Sung-Hyuk Song, Senior Scientist, Department of Robotics and Mechatronics, AI Robot Research Division, Korea Institute of Machinery and Materials

With the benefits of KIMM’s new technology, the gripper can even carry out complex tasks, such as inserting a paper cake topper into the cake, preparing for a party by packaging a doll in a gift box, and firmly holding matches to light candles. The gripper is also capable of arranging flowers by holding the stems of different flowers with atypical shapes placed on the floor.

Dr. Chanhun Park, the Director of AI Robot Research Division, explained, “Our newly developed elephant trunk-mimetic, pinch-suction fusion gripper, which uses both claw and suction mechanisms, is soft, so there is no risk of injury even when operating it around people.”

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. 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.

Dr. Chanhun Park, Director of AI Robot Research Division, Korea Institute of Machinery and Materials