Robot component technology has been developed that can create a universal gripper that can even pick up potato chips without breaking them, and a wearable elbow suit that reduces muscle strain.

A research team led by Professor Jiyoon Kim of the Department of Materials Science and Engineering and Professor Junbeom Bae of the Department of Mechanical Engineering at UNIST (President Yonghoon Lee) have developed a ‘soft valve’ technology, a component that can maximize the advantages of soft and flexible soft robots.

This tube-shaped component is a dual-function component that detects external stimuli and precisely controls the movement of the actuator without electricity.

It can operate without electricity, making it safe for use underwater or in spark-prone environments. Dual-function components allow for lightweight robots. The price is also affordable, at around 800 won per part.

Professor Kim Ji-yoon explained, “Unlike the soft and flexible body of the soft robot, the stimulus detection sensors and drive control components are often still made of hard electronic components. However, through this research, we were able to make the sensors and drive control components out of soft and flexible materials.”

The research team used this soft valve to create a universal gripper that can easily pick up a variety of objects. These grippers were able to pick up everything from potato chips, which would easily crumble with a sturdy robotic hand, to heavy, bulky pieces of wood. They even performed well in sparking environments and underwater.

Additionally, a wearable elbow-assist robot was created using this component, effectively reducing arm muscle strain. This device automatically increases elbow assistance based on the angle of the user's arm bend. When worn, the robot was found to reduce elbow force by an average of 63%.

This soft valve operates by moving the actuator through air flowing through the tube. Pulling the end of the tube presses a spiral thread inside the tube, controlling the inflow and outflow of air. Pulling the end of the tube causes the actuator to expand and contract like an accordion windpipe.

The research team also confirmed that by precisely programming the structure and number of threads wound around the tube, air inflow and outflow can be varied. Even with the same force applied to the tube's end, the actuator can be adjusted appropriately depending on the shape and number of threads wound.

Professor Bae Jun-beom of the Department of Mechanical Engineering explained, “The developed component can be easily used through material programming without electronic components, so it will greatly contribute to the development of various wearable systems.”

This study was published online on July 4, 2023, in Nature Communications, a globally renowned academic journal. The research was supported by the National Research Foundation of Korea (NRF) under the Ministry of Science and ICT, the Korea Institute of Materials Science (KIMS), and the Korea Evaluation Institute of Industrial Technology (KEIT).