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Lookup NU author(s): Dr Weicheng Huang
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2026 The Authors.Cerebral aneurysms are dilations of brain blood vessels that can cause a life-threatening stroke upon rupture. Embolization is a widely used treatment in which embolic agents (e.g., coils, particles) are delivered through a mechanical catheter to occlude the aneurysm. However, conventional catheter-based embolization faces delivery challenges in narrow and tortuous vasculature. Recently, magnetically actuated soft robots have emerged as a promising strategy for robotic embolization due to their ability to access hard-to-reach vascular regions. In particular, tangentially magnetized magnetic fiberbots (MFBs) can elongate to navigate through confined vessels and subsequently aggregate under a reversed magnetic field to enable aneurysm occlusion. Unlike conventional helical robots with single-direction magnetization, the mechanics governing this elongation–aggregation shape morphing under frictional confinement remain poorly understood, making the magnetic control of stably retained aggregation difficult. To elucidate the dual-mode shape morphing of MFBs, we establish a magneto-mechanical framework by coupling Kirchhoff rod elasticity with distributed magnetic torques and frictional rod–wall contact. Then, we develop a reduced analytical theory for the elongation response under a magnetic field aligned with the initial net magnetic moment. Under a reversed magnetic field, the coupled effects of magnetic actuation and frictional confinement give rise to aggregation or reversed elongation, while subsequent unloading determines whether aggregation is recoverable or retained. To resolve these geometrically nonlinear deformations, we adopt the discrete elastic rod (DER) method for numerical simulations and perform a parametric analysis to quantify how helix geometry and frictional confinement affect the critical magnetic fields governing retained aggregation. Both the analytical theory and the numerical simulations are validated by experiments, demonstrating their accuracy and effectiveness. These findings offer theoretical guidance for accurate magnetic control of MFBs in stable robotic embolization.
Author(s): Wan S, Tong D, Chen H, Li J, Sun X, Gong Z, Huang W, Wang L
Publication type: Article
Publication status: Published
Journal: International Journal of Engineering Science
Year: 2026
Volume: 228
Print publication date: 01/11/2026
Online publication date: 07/07/2026
Acceptance date: 27/06/2026
Date deposited: 20/07/2026
ISSN (print): 0020-7225
ISSN (electronic): 1879-2197
Publisher: Elsevier Ltd
URL: https://doi.org/10.1016/j.ijengsci.2026.104623
DOI: 10.1016/j.ijengsci.2026.104623
Data Access Statement: Data will be made available on request.
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