World's First Low-Power, Ultra-Compact Water Surface Robot Development Success

Professor Jo Jin-han of Korea University and Professor Go Je-seong of Ajou University Team

[Asia Economy Reporter Kim Bong-su] The Ministry of Science and ICT announced on the 27th that Professor Cho Jin-han's research team (Korea University) and Professor Ko Je-sung's research team (Ajou University) have secured technology to fabricate high-conductivity and highly stretchable hydrogel electrodes, successfully developing high-performance, low-power soft actuators and ultra-small aquatic robots.

Hydrogels are attracting attention as key materials for next-generation ultra-small robot actuators due to their excellent functionality and stimulus responsiveness. However, since they operate based on changes in internal osmotic pressure when external stimuli are applied, their actuation speed is slow, and movement control is difficult, limiting their application in complex robotic systems. While electrical stimulation could potentially improve performance, the high water content characteristic of hydrogels restricts effective methods for applying electrical stimuli.

The research teams uniformly coated an electrode layer on the hydrogel surface and fabricated wrinkled electrodes by utilizing the hydrogel's contraction phenomenon. Through this, they succeeded in simultaneously achieving high electrical conductivity and stretchability, confirming the feasibility of using it as a soft actuator. Compared to existing soft actuators that require high voltages above 1,000 volts [V], the developed soft actuator operates at low voltages below 3 volts [V], and in terms of performance, it possesses over 100 times higher energy density and more than 10 times higher power density.

Because the developed soft actuator delivers high performance with only a small battery, it can be applied to ultra-small and ultra-lightweight robots. The research teams successfully applied this to an actual robot, developing an ultra-small aquatic robot capable of operating underwater.

A representative of the research teams stated, “The operating principle revealed by this research is the first of its kind in the world,” adding, “Soft actuators operating at low voltage and low power are expected to be applicable to various small environmental exploration robots and medical devices in the future.”

The research results were published on the same day in the international academic journal Science Robotics.