Soft robots, medical devices, and wearable devices have become a part of our daily lives. KAIST researchers have developed a fluid switch using ionic polymer artificial muscles that operates at ultra-low power and produces a force 34 times greater than its weight. Fluid switches control the flow of fluid in a specific direction to enable various movements.
KAIST (President Kwang-Hyung Lee) announced on the 4th of January that a research team led by Professor IlKwon Oh from the Department of Mechanical Engineering has created a soft fluidic switch that operates on ultra-low voltage and can be utilized in narrow spaces.
Artificial muscles imitate human muscles and provide flexible and natural movements compared to traditional motors. They are essential components used in soft robots, medical devices, and wearable devices. These artificial muscles respond to external stimuli such as electricity, air pressure, and temperature changes to generate movements. Precise control of these movements is crucial for utilizing artificial muscles effectively.
Existing motor-based switches were challenging to use in confined spaces due to their rigidity and large size. To address these issues, the research team developed an electro-ionic soft actuator that can control fluid flow and generate significant force, even in narrow pipes, and utilized it as a soft fluidic switch.
The ionic polymer artificial muscle developed by the research team consists of metal electrodes and ionic polymers. It responds to electricity by generating force and movement. The researchers used a polysulfonated covalent organic framework (pS-COF), which combines organic molecules on the surface of the artificial muscle electrode, to generate an impressive amount of force relative to its weight with ultra-low power (~0.01V).
As a result, the thin artificial muscle, with a thickness of 180 µm (as thin as a hair), produced a force more than 34 times greater than its weight of 10 mg, enabling smooth movement. This allowed the research team to precisely control the direction of fluid flow using low power.
Professor IlKwon Oh, the leader of this research, stated, “The electrochemical soft fluidic switch that operates at ultra-low power opens up numerous possibilities in the fields of soft robots, soft electronics, and microfluidics based on fluid control.” He added, “From smart fibers to biomedical devices, this technology can be immediately applied to various industrial settings as it can be easily integrated into ultra-small electronic systems used in our daily lives.”
The results of this study, with Dr. Manmatha Mahato, a research professor in the Department of Mechanical Engineering at KAIST, as the first author, were published in the international academic journal Science Advances on December 13, 2023. (Paper title: Polysulfonated Covalent Organic Framework as Active Electrode Host for Mobile Cation Guests in Electrochemical Soft Actuator)
This research received support from the National Research Foundation of Korea’s Leader Scientist Support Project (Creative Research Group) and Future Convergence Pioneer Project.
