Collective Reconfiguration and Propulsion Behaviors of <i>Chlorella</i>-Based Biohybrid Magnetic Microrobot Swarm

Magnetic microrobots hold great promise for applications in drug delivery and environmental remediation, but achieving collective reconfiguration and effective propulsion for dense, motile magnetic microrobots remains a significant challenge. In this research, we have fabricated <i>Chlorella</i>-based biohybrid magnetic microrobots in bulk using a facile biotemplating process and studied their superior reconfiguration and propulsion performance. Our results show that the dispersed superparamagnetic individuals can self-organize into a swarm of chain-like multimers, achieving effective propulsion via rolling or tumbling modes. The near-bound locomotion process demonstrates pseudochiral periodic reciprocation properties, and a detailed morphological analysis has been conducted. Furthermore, the microrobots can form vortices and realize swarm propulsion in spinning mode. These findings indicate that the spheroidal microrobots exhibit high maneuverability in programmable self-assembly, collective reconfiguration, and swarm propulsion based on dynamic magnetic interactions. In summary, this research provides a feasible method for constructing reconfigurable magnetic microrobots and explores an applicable paradigm for their flexible swarm control and collective cooperation. These advances have significant implications for practical applications of magnetic microrobots in various fields.