Bioinspired Superhydrophobic Swimming Robots with Embedded Microfluidic Networks and Photothermal Switch for Controllable Marangoni Propulsion

• Published in: Advanced functional materials Vol. 33; no. 6
• Main Authors: Mao, Jiang‐Wei, Han, Dong‐Dong, Zhou, Hao, Sun, Hong‐Bo, Zhang, Yong‐Lai
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.02.2023
• Subjects: Actuation; Air chambers; Channels; Controllability; Digital cameras; Fuels; Graphene; Hydrophobic surfaces; Hydrophobicity; Insects; laser irradiation; Marangoni convection; Marangoni propulsion; Materials science; Microfluidics; photothermal switches; Polydimethylsiloxane; Propulsion; Robotics; Robots; Route planning; Surface tension; Swimming; swimming robots; Water resistance
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202208677

Chemical Marangoni propulsion enables dynamic and untethered motion by generating surface tension gradient through chemical release, thereby having great potential for the development of insect‐scale self‐propelled robots. However, as the release and diffusion of chemical “fuels” are commonly uncontrollable, the Marangoni propulsion is unstable, thereby restricting robotic applications. Herein, the laser fabrication of superhydrophobic swimming robots to develop controllable Marangoni propulsion based on a photothermal composite of graphene and polydimethylsiloxane is reported. By combining the microfluidic channels with photothermal air chambers, a light‐triggered switch that can control the release of chemical “fuels” is proposed. Furthermore, a superhydrophobic surface is fabricated on the swimming robot by laser treatment, which reduced water resistance and promoted propulsion. On‐demand actuation and swimming route planning are realized by programming the alcohol/air segments in the releasing channels, on‐demand actuation and swimming route planning have been realized. As a proof‐of‐concept, a Marangoni swimming robot equipped with a miniature digital camera is used in an actual environment. Therefore, this study is expected to advance the practical applications of the chemical Marangoni effect in swimming robots. Microfluidics‐enabled superhydrophobic swimming robots that enable controllable Marangoni propulsion are fabricated, in which photothermal air chambers are proposed as light‐responsive switches for controllable chemical release. By programming, the alcohol/air segments, on‐demand actuation, and swimming route planning are realized. Proof‐of‐concept Marangoni swimming robot equipped with a miniature digital camera are driven in the wild environment.