Magnetic micro/nano robots for physical cell stimulation: fundamentals, fabrication, and applications

Cell stimulation plays a critical role in regulating essential cellular processes such as differentiation, migration, and apoptosis. Among various stimulation methods, magnetic micro/nano robots (mMNRs) have gained attention for their ability to precisely stimulate cellular and intracellular structures, owing to their structural flexibility and remote actuation. While much of the research on mMNRs has focused on their use for chemical stimulation of cells, particularly for targeted drug delivery, increasing attention is now given to their potential for physical stimulation of cells. As one form of physical stimulation, mechanical cell stimulation, particularly for cancer therapeutics, has been discussed in existing reviews. This article presents a comprehensive review of the most recent advances in mMNR-mediated physical cell stimulation, including mechanical, thermal, and electrical stimulation, and highlights their emerging roles in cancer therapy, regenerative medicine, neuromodulation, and antimicrobial treatment. The fundamentals of magnetic material-field interactions and actuation mechanisms are discussed, followed by fabrication strategies for structurally diverse mMNRs. Biomedical applications driven by mMNR-mediated cell stimulation are then discussed, along with remaining challenges and opportunities. By highlighting the unique capabilities of mMNRs in physical cell stimulation, this review emphasizes their potential in advancing both biological research and biomedical applications.