Polymer-Based Swimming Nanorobots Driven by Chemical Fuels

Field-driven biomedical micro-/nanorobots have attracted significant attention over the past decades because of their potential promises to be controlled toward hard-to-reach tissues for various biological and medical usages including active targeted drug/gene delivery, detoxification, and nanosurgery. Learning from biological molecular motors such as kinesin, which exert the autonomous motion though spontaneous hydrolysis of adenosine triphosphate into mechanic movement. Substantial efforts toward the development of chemically powered swimming micro-/nanorobots have recently demonstrated the capability of converting chemical energy into mechanical motion based on a fuel solution. In spite of the great promise, the major materials of the past chemical swimming micro-/nanorobots are primarily based on metals or metallic oxide with poor biocompatibility and biodegradability. With the envision of Richard Feynman, who imagined the fabrication of micro- and nanoscale machines by rearranging atoms and molecules, considerable efforts were devoted toward the chemical micro-/nanorobotics based on polymers with bottom-up techniques such as layer-by-layer molecular assembly and supramolecular assembly. In this chapter, we summarize the recent advances on investigating the fabrication of polymer-based micro-/nanorobots using bottom-up approaches and various aspects of their chemically powered propulsion including the propulsion mechanism, movement guidance, and chemotaxis. We also highlight the emerging technological approaches to enhance the navigation performances of micro-/nanorobots. The recent demonstrations of autonomous self-seeking motion and biomedical applications of such micro-/nanorobots are introduced. We conceive that perpetual polymer and fabrication innovations with interdisciplinary efforts can drive us closer to the fantasy of “swallowing surgeons.”