Dual-mode driven Marangoni actuator with spontaneity and controllability as a soft robot

The investigation of Marangoni effect-driven actuators holds significant importance due to their wide-ranging applications in smart devices and biomedical fields. However, traditional Marangoni hydrogel actuators often lack spontaneity and are difficult to control. In this study, we designed and prepared a dual-mode driven Marangoni hydrogel actuator (DDMA) which combines the spontaneity of solvent exchange-based hydrogel actuators with the controllability of photothermal-based ones. DDMA not only exhibits excellent ethanol loading capacity but also demonstrates both sustained motion for approximately 21 minutes and rapid motion. Furthermore, controlled motion can be achieved under infrared light, by adjusting the illumination point, the hydrogel can navigate through complex N-shaped mazes and achieve turning angles exceeding 180°. This spontaneously controllable potential of hydrogel motion holds great promise in the field of intelligent transportation and soft robotics technology.