Additive manufacturing (AM) is characterized by a high degree of design freedom and individualization and is therefore ideally suited for the production of specimens for biomedical research. A fast and cost-effective process for producing medical specimens is the DLP process, in which the specimen is created layer by layer from light-curing photopolymer. This process can be used to fabricate parts from a wide range of materials with high detail and precision. In addition, the mechanical, electrical, magnetic, or optical properties of the photopolymers can be influenced by incorporating additives [1-3]. Additives are materials that are dissolved or dispersed in small quantities in the photopolymer to induce and adjust desired material properties.

Different magnetic composites of liquid photopolymer and homogeneously distributed magnetic nanoparticles (MNP) as a magnetic additive were prepared using a special synthesis reactor. For process and quality control, established magnetic measurement methods were used (linear and non-linear dynamic susceptibility together with static magnetization measurements). A homogeneity demonstrator was developed composed of ten standard specimens stacked in building direction. Magnetic analysis of the individual standard hybrid material specimens showed that no sedimentation of the MNP occurred during the manufacturing process (duration 8 h, height 10 cm) for any of the fabricated magnetic composites. However, the investigation of the magnetic properties revealed an unexpected easy plane anisotropy in the individual standard sample bodies. This means that the MNP prefer to align their magnetic moments in the printing plane. Results show that the formation of magnetic easy plane anisotropy in the AM process is influenced by the MNP type and concentration used.

We further present how these special fundamental properties of additively manufactured two-dimensional magnetic materials will be exploited in future medical imaging.

References:

[1] A. Ruiz; S. Garg; S. Streeter, M.K. Giallorenzi, E. LaRochelle, K. Samkoe; B.W. Pogue Sci. Rep., 2021, 11, 17135.

[2] M. C.-Gonzalez; A. D.-Alfaro; N. L.-Larrea; N. Alegret; D. Mecerreyes ACS Appl. Poly. Mater., 2021, 3, 2865-83.

[3] N. Löwa, J.M. Fabert; D. Gutkelch; H. Paysen; O. Kosch; F. Wiekhorst J Magn.Magn.Mater., 2019, 469, 456-60.

Acknowledgement:

This project was funded by the Federal Ministry for Economic Affairs and Climate Action within the TransMeT project “NANORM”.