Material–Structure Synergistic Design for High-Speed Magnetically Actuated Helical Microrobots

Objectif

Cancer remains a leading cause of mortality, with over 90% of drug candidates failing clinical translation, often due to systemic toxicity from non-specific delivery. Magnetic helical microrobots (H-MMRs) offer a promising solution by enabling remote-controlled, minimally invasive navigation and localized drug release. However, their clinical translation is severely limited by speed: current H-MMRs achieve locomotion comparable to E. coli (~5–10 body lengths/s), far below high-performing microorganisms (~200–500 bl/s), and are unable to navigate millimetre-scale vessels under physiologically relevant blood flow (>10 cm/s). This speed limitation stems from the step-out frequency (ω_step-out), beyond which hydrodynamic drag overwhelms magnetic torque, leading to loss of synchronization.This project aims to overcome this barrier by establishing a material–structure synergistic design paradigm for high-speed H-MMRs (Hi-HMRs). Specifically, I will (i) enhance magnetic torque via 3D nanopatterning of biocompatible Fe-based soft magnetic alloys, exploiting focused electron beam-induced deposition (FEBID) for sub-100 nm precision; (ii) investigate nanoscale 3D spin textures in helical structures using advanced magneto-optical and synchrotron-based techniques (3D-MOKE, XMCD-PEEM) combined with micromagnetic simulations to optimize torque generation; and (iii) develop a novel magneto–fluid–structure interaction (MFSI) framework that integrates 3D magnetic topology with fluidic drag modelling, enabling rational co-design of helical geometry and material properties.By pushing the operational limits of H-MMRs beyond current step-out constraints, this research will deliver fundamental insights into high-speed microscale propulsion, while laying the technological foundation for their use in targeted intravascular therapies. The project addresses key MSCA priorities by advancing interdisciplinary science, fostering innovation, and contributing to biomedical technologies.