Optoelectronically Enabled Simultaneous and Decoupled Navigation and Selective Pairing of Electrically Driven Janus Particles for Multi-Agent Microrobotics

Abstract

Self-propelled Janus particles are promising active agents for microscale manipulation and microrobotic applications. However, when powered by a global external energy source, such as an electric, magnetic, or optical field, all particles respond simultaneously, preventing their independent and concurrent control. Achieving parallel, decoupled control without continuous particle-specific feedback, while preserving intrinsic self-propulsion, remains a significant challenge. Here, we present an optoelectronic (OE) strategy for simultaneously and independently controlling electrically driven, self-propelled metallo-dielectric Janus particles (JPs) using spatially programmable virtual electrodes. These electrodes are generated by projecting a single predefined illumination pattern from a digital micromirror device onto a photoconductive surface. The resulting confinement landscape enables multiple JPs to follow distinct trajectories without continuous monitoring, feedback, or pattern reconfiguration. We demonstrate controlled pairing of JPs with passive polystyrene particles and biological cells. For automated multi-agent operation, an image-based assignment framework identifies optimal agent-target pairs, excludes intersecting trajectories, and generates a single composite pattern for simultaneous, selective pair formation without real-time updating. Finally, we demonstrate independent manipulation of multiple magnetically rolling JPs under a globally applied magnetic field. Overall, this programmable open-loop strategy provides a versatile framework for multi-agent microrobotic manipulation, with potential applications in in-vitro micromanipulation and microfluidic systems.