Micro‐ and nanorobots from magnetic particles: Fabrication, control, and applications

Abstract Magnetic microparticles (MPs) and nanoparticles (NPs) have long been used as ideal miniaturized delivery and detection platforms. Their use as micro‐ and nanorobots (MNRs) is also emerging in the recent years with the help of more dedicated external magnetic field manipulations. In this review, we summarize the research progress on magnetic micro‐ and nanoparticle (MNP)‐based MNRs. First, the fabrication of micro‐ and nanorobots from either template‐assisted NP doping methods or directly synthesized MPs is summarized. The external driving torque sources for both types of MNRs are analyzed, and their propulsion control under low Reynolds number flows is discussed by evaluating symmetry breaking mechanisms and interparticle interactions. Subsequently, the use of these MNRs as scientific models, bioimaging agents, active delivery, and treatment platforms (drug and cell delivery, and sterilization), and biomedical diagnostics has also been reviewed. Finally, the perspective of MNPs‐based MNRs was outlined, including challenges and future directions.