Abstract
•Geometries are compatible with 3d printing via fused deposition modeling (FDM)•In-line magnetic annealing of filament during extrusion process.•Magnetic annealing can increase the performance of magnetorheological elastomers.•Uniform magnetic fields increase magnetic anisotropy and magnetoactive properties.•Non uniform magnetic fields decrease magnetic anisotropy and overall performance.
Magnetorheological elastomers (MREs) are magnetoactive smart materials that exhibit mechanical deformation in the presence of magnetic fields. The greatest performance in these materials has been seen from magnetic annealing, which creates high internal anisotropy. This work studies how different magnetic annealing setups (no field, uniform field, and non-uniform field) can be applied to thermoplastic MRE extrusion geometries and how each setup affects the resulting magnetic and magnetoactive properties. The uniform field resulted in an increase of both magnetic anisotropy and magnetoactive performance when compared to no field (but was difficult to make samples with). The non-uniform magnetic annealing setup resulted in similar magnetic properties but decreased magnetoactive performance when compared to the no field samples likely due to interference with the naturally occurring anisotropy that results from extrusion flow. This work demonstrates that certain magnetic annealing setups can be applied to extrusion geometries for increased anisotropy effects resulting in greater magnetoactive response compared to no magnetic annealing, while others can lead to a decrease in anisotropy and less magnetoactive response.