Dynamic control and structural manipulation of magnetic micro- clusters in a suspension are essential for their applications in stroke treatment, fluidic actuators and smart materials. Due to their anisotropic shape and magnetism, ferromagnetic micro-rod clusters (FMRCs) exhibit unique behaviors under both static and dynamic magnetic fields. The results are summarized here: (1) A rotation-extension coupled motion of FMRCs can be triggered by a static magnetic field, which results in a rearrangement of FMRCs; (2) A structural transition of FMRCs from stripy patterns to cellular network can be controlled by a transverse magnetic field; (3) Molecular diffusivity can be enhanced by rotating FMRCs, which eventually accelerates diffusion-limited thrombolysis and reduces risks of stroke treatment.
