Soft robots with soft sensors and valves
A research team has developed a novel “soft valve” technology that can integrate sensing and control functions in soft robots without using any electricity. The technology enables soft robots to perform tasks that require inherent safety and adaptability, such as picking up fragile items or assisting human movements.
The soft valve is a tube-shaped component that can detect environmental inputs and precisely control driving motion using just air pressure. The component works by directing airflow through a helically coiled thread inside the tube. When stress is applied to one end of the tube, the thread contracts, controlling air entrance and outflow. This accordion-like action enables precise and flexible movements without the use of electricity.
The research team demonstrated various applications that utilize this groundbreaking technology. They created universal tongs that can gently pick up delicate items like potato chips, avoiding breakage caused by excessive force exerted by traditional rigid robot hands.
They also used these all-soft components to make wearable elbow assist robots, which are designed to reduce muscle strain caused by repetitive tasks or strenuous activities involving arm movements. The elbow support automatically adjusts based on the angle at which a person’s arm is bent—an innovation that contributes to a 63 per cent average reduction in the force placed on the elbow when wearing the robot.
Advantages of soft valve technology
The soft valve technology has several advantages over conventional methods of integrating sensing and control systems in soft robots. First, it maintains complete softness, form factor, or capabilities of the soft robot body, unlike rigid electrical components that may compromise these features. Second, it enables safe operation underwater or in places where sparks may pose a problem, while also reducing weight loads on robotic systems by eliminating the need for electricity-dependent components. Third, it is cost-effective, as each component is priced at around 800 Won.
The research team hopes that their technology will open up new possibilities for soft robotics in various fields and applications. They also plan to further improve the performance and functionality of their soft valve components by exploring different materials and designs.
About the research team
The research team consists of Professor Kim Sang-Hee from Seoul National University’s Department of Mechanical and Aerospace Engineering, Professor Lee Seung-Hwan from Korea Advanced Institute of Science and Technology’s Department of Mechanical Engineering, and Professor Kim Kyu-Jin from Seoul National University’s Institute of Advanced Machines and Design. They published their findings in the journal Science Robotics on September 15, 2023.
The research was supported by the National Research Foundation of Korea (NRF) and the Ministry of Science and ICT (MSIT).
