State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
Jianhua Zhang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
Zhen Wu
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
Sinan Du
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
Zexin Zhang
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China; Corresponding author
Leilei Xu
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
Jianguo Guan
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China; Corresponding author
Summary: Inspired by astonishing collective motions and tactic behaviors in nature, here we show phototactic flocking of synthetic photochemical micromotors. When enriched with hydroxyl groups, TiO2 micromotors can spontaneously gather into flocks in aqueous media through electrolyte diffusiophoresis. Under light irradiation, due to the dominant nonelectrolyte diffusiophoretic interaction resulting from the overlap of asymmetric nonelectrolyte clouds around adjacent individuals, these flocks exhibit intriguing collective behaviors, such as dilatational negative phototaxis, high collective velocity, and adaptive group reconfiguration. Consequently, the micromotor flocks can migrate along pre-designed paths and actively bypass obstacles with reversible dilatation (expansion/contraction) under pulsed light navigation. Furthermore, owing to the enhanced driving force and rapid dilatational area covering, they are able to execute cooperative tasks that single micromotors cannot achieve, such as cooperative large-cargo transport and collective microenvironment mapping. Our discovery would promote the creation of reconfigurable microrobots, active materials, and intelligent synthetic systems. : Chemistry; Catalysis; Nanoparticles Subject Areas: Chemistry, Catalysis, Nanoparticles
