Bioinspired superoleophobic miniaturerobots and their multiple functions at the oil–water interface

Miniature robots have important applications in fields such as cargo transportation, environmental detection, and energy exploration. In particular, miniature robots that can swim in oil water systems have great potential for droplet manipulation or cargo assembly. However, the need to impart high antiwetting and low oil adhesion properties to these robots still severely hinders their movement in oil water systems. In this work, we prepared underwater-superoleophobic miniature robots using an ultrafast oxygen plasma treatment, which requires only 8 s of surface modification. Owing to their underwater superoleophobicity, the robots can swim at the oil water interface and perform cargo transport, assembly, and rotation, as well as transport oil droplets underwater. In addition, under magnetic fields (20–60 mT), the strider robot can swim and jump at the oil water interface, demonstrating flexible, responsive motion. These findings demonstrate that our rapidly fabricated, multifunctional miniature robots possess excellent interfacial mobility and controllability, suggesting promising applications in oil–water systems.