Description
Microfluidic devices have become indispensable tools for chemical analysis, diagnostics, and single-cell studies due to their precise control over small volumes, boundary conditions, and physicochemical environments. However, most microfluidic systems remain fundamentally passive: their functionality is largely dictated by fixed channel geometries, static electrodes, and externally imposed flow fields. At the same time, recent roadmaps in micro- and nanorobotics [1] emphasize that despite major advances in propulsion and functionality, practical deployment of microrobots is still limited by challenges in control, reliability, scalability, and system-level integration. Integrating microrobots directly into microfluidic devices offers a natural and powerful pathway to address these challenges, enabling active, adaptive lab-on-a-chip systems in which mobile agents complement—and fundamentally extend—the capabilities of the underlying microfluidic architecture. When embedded within microfluidic environments, microrobots benefit from confinement, well-defined interfaces, and globally applied fields, which together enhance stability, addressability, and functional robustness. Field-driven Janus microrobots are particularly well suited for such integration. Electrically powered metallodielectric Janus particles enable fuel-free propulsion under uniform electric fields and act as mobile microelectrodes, locally amplifying electric fields and gradients. This capability enables label-free cargo manipulation via dielectrophoresis, selective transport of synthetic [2] and biological payloads, and spatially localized interactions with cells and subcellular components. Within microfluidic devices, these mobile functionalities enable operations that are difficult or impossible to realize using static structures alone, including targeted electroporation [3], enhanced gene and molecular delivery, selective organelle manipulation, and programmable single-cell interrogation. The integration of microrobots into microfluidic devices becomes substantially more powerful when hybrid magnetic–electric [4] or opto-electronic [5] actuation is employed. Magnetic fields provide robust steering, rolling, and navigation across a wide range of solution conductivities, while electric fields offer frequency-tunable propulsion modes, reversible cargo loading and release, and controllable surface interactions. When combined with closed-loop feedback control, this hybrid framework enables precise and repeatable navigation of individual microrobots within microfluidic chambers, overcoming particle-to-particle variability under global actuation and addressing a key limitation identified in current microrobotics roadmaps. Overall, integrating microrobots into microfluidic devices shifts lab-on-a-chip platforms from passive flow-based systems to active, reconfigurable microsystems. This synergy directly addresses critical bottlenecks in microrobotics—control, reproducibility, and functional integration—while enabling new modes of manipulation, interaction, and automation with significant implications for single-cell analysis, targeted delivery, and next-generation microfluidic technologies.
[1] X. Ju, et al., Technology Roadmap of Micro/Nanorobots, ACS Nano, 19, 27, 24174–24334 (2025).
[2] S. Park and G. Yossifon, Micromotor-Based Biosensing Using Directed Transport of Functionalized Beads, ACS Sensors 5 (4), 936-942 (2020).
[3] Y. Wu, A. Fu, G. Yossifon, Micromotor-based localized electroporation and gene transfection of mammalian cells, PNAS, 118, 38, e2106353118 (2021).
[4] Y. Wu, S. Yakov, A. Fu, G. Yossifon, A Magnetically and Electrically Powered Hybrid Micromotor in Conductive Solutions: Synergistic Propulsion Effects and Label-Free Cargo Transport and Sensing, Adv. Sci., 2204931 (2022).
[5] S. S. Das G. Yossifon, Optoelectronic Trajectory Reconfiguration and Directed Self-Assembly of Self-Propelling Electrically Powered Active Particles, Adv. Sci., 2206183 (2023).