Geometry-based enhancement of magnetic flux density for targeted drug delivery using an optimized double-conical core

Background/problem A major challenge in Magnetic Drug Targeting (MDT) is generating sufficient magnetic flux density at tissue depth without prohibitive energy costs. While most solutions focus on active systems, the potential of geometry–based enhancement through magnetic core design remains underexplored. Objective/methods This study investigates the hypothesis that optimizing the core’s geometry and applying flux–confinement shielding can power-neutrally concentrate magnetic flux. We systematically evaluated five core configurations using finite element analysis and experimental validation. Results We demonstrate that a magnetic core with two conical tips and full flux–confinement shielding (except at the tips) yields a superior magnetic flux density in the target air gap, showing an increase of 108% compared to a standard flat-tip design. This power-free enhancement is achieved solely through core geometry and flux confinement, without increasing the electrical input to the coil. Conclusion/significance The proposed double-conical core design with high-permeability flux-guiding layers provides a practical, power-neutral approach for enhancing MDT system performance. This geometry-based strategy, not previously reported for MDT applications, directly addresses a key limitation hindering clinical translation.