Diffusion-Plating Al₂O₃ Film for Friction and Corrosion Protection of Marine Sensors

To extend the service life of sensors in seawater, this work prepared an integrated diffusion-plated Al₂O₃ film using high-power impulse magnetron sputtering (HiPIMS). The tribological properties of the Al₂O₃ film in a marine environment were tested using a tribometer. The morphology and evolution of the Al₂O₃ film before and after the friction tests were investigated by characterization techniques such as field emission scanning electron microscopy (FESEM). The results demonstrate that the Al₂O₃ film exhibits excellent tribological performance in the marine environment, significantly enhancing the wear resistance of the substrate material. Furthermore, with the protection of the Al₂O₃ film, the designed pressure sensor achieved high-sensitivity detection of minute operational forces underwater. When applied to a robotic gripper for manipulation tasks, the coated underwater sensor enabled accurate perception of subtle motion states of the grasped objects.