Microswimmers from Toposelective Nanoparticle Attachment

Microrobots hold promise for applications ranging from targeted delivery to enhanced mixing at the microscale. However, current fabrication techniques suffer limited throughput and material selection. Here, we demonstrate a versatile route enabling synthesis of microrobots off-the-shelf micro- nano-particles. Our protocol hinges on toposelective attachment photocatalytic nanoparticles onto microparticles, exploiting multi-functional polymer Pickering-wax emulsification step, yield large quantities photo-responsive active Janus particles. The presents both silane nitrocatechol groups, binding silica microspheres range metal oxide nanoparticles. emulsions protect part microspheres' surface, asymmetric functionalization, as required self-propulsion. resulting display characteristic orientation-dependent 3D motion upon UV illumination, different that conventionally described in literature. By connecting extensive library heterogeneous nanoparticle photocatalysts with nascent field matter, this platform lays groundwork towards designer microrobots, which can swim by catalysing broad chemical reactions potential future applications.