3D Printing of Flexible Composites via Magnetophoresis: Toward Medical Application Based on Low‐Frequency Induction Heating Effect

In this work, a commercial extrusion 3D printer is used to process magnetic pastes into desired 3D structures. The magnetic pastes prepared in the authors' laboratory are mixtures of Fe3O4 (iron oxide), microparticles, and PDMS (polydimethylsiloxane) polymer. After multiple composition tests, they produced pastes compatible with the 3D printer that can be additively manufactured into flexible ferromagnetic samples. The design optimization, together with the characterizations of composites, are investigated. Magnetic particles do not simply mix with the polymer but formed a chain‐like structure under the influence of a magnetic field during the printing process. The chain‐like structure induces magnetic and thermal anisotropies. The relative permeability and the low‐frequency induction heating (LFIH) effect are improved. The authors' development is highly relevant in healthcare applications, especially endovascular ablation for varicose treatment. Here extrusion‐based printing technique with magnetic alignment capability is reported. Optimization of the filed direction and magnitude are explored to get the best compromise between the material performance as well as its shape fidelity. Successful heating temperature has been achieved through the 3D printed composite, confirming high reliability of the proposed approach in application of endovenous thermal ablation.