Engineering and Controlling Bioinspired and Biohybrid Magnetic Microrobots Made From Living and Synthetic Materials

Delivering drugs effectively to targeted diseased sites remains a major challenge. Transmitting magnetic fields to guide drug carriers to specific locations is promising, however, current methods often struggle with physiological barriers and are limited to accessible areas. This presentation explores the engineering of magnetic microrobots powered by scalable torque-based actuation via rotational magnetic fields to enhance drug delivery to deep-seated tumors. This approach is particularly effective for microrobots with high anisotropy, which can be boosted by both the shape and magnetocrystallinity of the magnetic materials used. We demonstrate biohybrid microrobots—live bacteria augmented with magnetic nanomaterials—that combine chemotaxis as autonomous navigation with external magnetic control. This hybrid strategy improves tumor targeting compared to unactuated controls and can be optimized with spatially restricted rotating magnetic fields to reduce side effects. Additionally, we have developed synthetic microrobots from biodegradable hydrogels engrafted with patterns of magnetitenanoparticles. By applying dynamic magnetic fields during microfluidic fabrication, we create anisotropic capsule-like microrobots with strings of nanoparticles. These microrobots, actuated with rotational magnetic fields, effectively dissolve thrombi in vascular models and induce convection enhanced drug transport. These advances offer promising improvements in drug delivery and may advance the clinical use of magnetic microrobots.