Premium
Rapid, High‐Resolution Magnetic Microscopy of Single Magnetic Microbeads
Author(s) -
McCoey Julia M.,
Gille Robert W.,
Nasr Babak,
Tetienne JeanPhilippe,
Hall Liam T.,
Simpson David A.,
Hollenberg Lloyd C. L.
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201805159
Subject(s) - magnetic force microscope , materials science , paramagnetism , magnetic nanoparticles , superparamagnetism , magnetization , bead , magnetic tweezers , magnetic resonance force microscopy , magnetic domain , magnetic particle inspection , microscopy , magnetic anisotropy , magnetic field , magnetic resonance microscopy , nanotechnology , condensed matter physics , optics , magnetic resonance imaging , nanoparticle , optical tweezers , ferromagnetic resonance , composite material , physics , medicine , quantum mechanics , spin echo , radiology
Magnetic microparticles or “beads” are used in a variety of research applications from cell sorting through to optical force traction microscopy. The magnetic properties of such particles can be tailored for specific applications with the uniformity of individual beads critical to their function. However, the majority of magnetic characterization techniques quantify the magnetic properties from large bead ensembles. Developing new magnetic imaging techniques to evaluate and visualize the magnetic fields from single beads will allow detailed insight into the magnetic uniformity, anisotropy, and alignment of magnetic domains. Here, diamond‐based magnetic microscopy is applied to image and characterize individual magnetic beads with varying magnetic and structural properties: ferromagnetic and superparamagnetic/paramagnetic, shell (coated with magnetic material), and solid (magnetic material dispersed in matrix). The single‐bead magnetic images identify irregularities in the magnetic profiles from individual bead populations. Magnetic simulations account for the varying magnetic profiles and allow to infer the magnetization of individual beads. Additionally, this work shows that the imaging technique can be adapted to achieve illumination‐free tracking of magnetic beads, opening the possibility of tracking cell movements and mechanics in photosensitive contexts.