Light-driven soft climbing robot based on negative pressure adsorption

Many organisms rely on a dynamic attachment mechanism to climb surfaces. Inspired by these organisms, researchers have developed soft climbing robots. Despite their rapid development in recent times, such robots have restricted application in complex environments, such as the lack of remote wireless actuation and attachment ability for climbing tilted or slippery surfaces. To address these issues, we report a light-driven dynamic adsorption/desorption soft suction cup inspired by rock-climbing fish (Beaufortia kweichowensis). Our suction cups utilize the volumetric change caused by changes in the gas–liquid phase in the inner chamber to generate suction and thrust. The repetitive changes in the gas–liquid phase, controlled by photothermal conversion, help achieve adsorption and desorption. We demonstrated that the suction cups based on negative pressure adsorption can easily help miniaturize soft robotic devices and adapt to multiple types of substrates, making our approach applicable to tilted or slippery surfaces. By integrating the soft suction cups for surface attachment by dynamic control and a shape memory alloy as a deformable body, we developed a soft climbing robot that can perform precise, facile, and programmed controlled climbing under different conditions via remote light manipulation. Four continuous and directional climbing sequences on tilted and slippery surfaces were demonstrated. The results are expected to help advance the application of light-driven soft robots on tilted or slippery surfaces