- Extending rheological characterization methods to very small length scales is of interest. AC susceptometry using magnetic nanoparticle probes has been proposed for measurement of frequency-dependent rheological properties at the nanoscale. As this technique has been primarily used for ideally Newtonian fluids, this research aimed to extend this technique to viscoelastic materials ranging from purely viscous (Newtonian) to purely elastic (Hookean). Polyethylene oxide, or PEO, was investigated as a representative viscoelastic material to be tested using the proposed AC susceptometry methods, and solutions of a high molecular weight PEO (POLYOX UCARFLOC 309) and a low molecular weight PEO (Sigma Aldrich, 200 K MW) were characterized. Frequency dependent properties of both solutions were obtained for both solutions using bulk-scale rheology techniques, and measurements of intrinsic viscosity were used to characterize the POLYOX 309 solution. VivoTrax magnetic tracer particles were also evaluated for their size distribution and mass dependence on magnetic susceptibility. Due to the inconsistencies observed in the frequency dependent measurements for the PEO 200K solution, additional study should be carried out to improve the characterization data. Further work to experimentally evaluate the frequency dependent behavior of polyethylene oxide using AC susceptometry methods is also necessary.