Self‐Propelled Rolled‐Up Polyelectrolyte Multilayer Microrockets

Abstract Engineering self‐propelled micro‐/nanomachines with ultrafast speeds and high towing forces is crucial for the efficient transportation of important objects in key biomedical and environmental applications. In this study, rolled‐up nanomembrane technology is used for the first time for the controlled fabrication of layer‐by‐layer (LbL)‐assembled microtubes and the corresponding chemical‐powered microrockets. By integrating LbL assembly, microcontact printing, and a rolled‐up nanomembrane technique, polyelectrolyte multilayer microplates of different shapes are transformed into well‐defined microtubes. Coupled with platinum nanoparticles, the as‐prepared microtubes can act as bubble‐propelled microrockets with a very rapid speed and a large towing force. As a proof of concept, the rolled LbL microrockets confirm the feasibility of transporting single or multiple cells at high speed. Integrating the rolled‐up nanomembrane technology and LbL assembly results in a simple, versatile, and low‐cost approach and expands the scope of both polymer multilayer‐based multifunctional tubes and artificial machines at the micro‐/nanoscale.