Magnetic Compartmentalized Microrobots: On-Chip Fabrication and Actuation of Dual-Core Magnetic Hydrogel Capsules

Magnetic microrobots have emerged as transformative tools for biomedical applications, particularly in targeted cargo delivery within confined environments. Despite their potential, existing systems lack the capability for co-encapsulation of various incompatible components in isolated compartments. In this paper, we propose a magnetic compartmentalized microrobot (MCM) fabricated on-chip with hydrogel. Our approach leverages a microfluidic aqueous two-phase system to create hydrogel capsules with dual cores, where two core flows composed of dextran and shell flow containing sodium alginate and magnetic particles are sequentially sheared by oil phase, crosslinked by calcium ion, and magnetized via an electromagnet, to produce MCMs massively. The resulting architecture enables separate encapsulation of incompatible components within two cores isolated by a hydrogel shell. Precise control over flow rates allows tunable sizing of both core and capsule dimensions. Under rotating magnetic fields, MCMs demonstrate programmable individual and collective behaviors, including directional motion, dispersion, and aggregation. We further characterize the system’s drug-release kinetics and swelling properties in simulated gastrointestinal environments. These findings highlight MCMs’ significant potential for tissue engineering, combinatorial drug delivery, and transport of incompatible bioactive agents. Note to Practitioners—The motivation of this work is to develop a magnetic microrobot with multiple isolated compartments for co-encapsulation and target delivery of various incompatible components. We built a microfluidic aqueous two-phase system to create magnetic hydrogel capsules with dual cores. Physical isolation between cores enables co-encapsulation of incompatible therapeutic agents. Magnetic actuation permits controlled individual and collective behaviors. Fully biocompatible composition coupled with scalable on-chip high-throughput fabrication ensures clinical relevance. These unique characteristics position the MCMs as promising candidates for biomedical applications requiring contamination-free co-delivery of multiple therapeutic payloads.