Magnetic Microstructures for Control of Brownian Motion and Microparticle Transport

A platform of microscopic magnetic wires and discrete bits of disks patterned on a surface offers dynamic control over the motion of fluid borne magnetic particles. The energy landscape associated with the local domain wall field originating from zigzag wire vertices is tuned by weak external fields to vary Brownian trajectories between strong confinements and delocalized spatial excursions. The corresponding spatial coverage of single particle trajectories allows the energy profile of such a magnetic trap to be mapped. Remote manipulation and guided transport of these objects across various opaque and transparent rigid surfaces as well as flexible films supporting discrete magnetic disks is presented.