Automated Actuation of Biodegradable and Self-Fluorescent Chlorella Swarms Using Magnetic Tweezers.

Magnetic microrobot swarms have broad application prospects in human-targeted therapy. However, the automated assembly and actuation of functional large-volume swarms is a challenging topic. Chlorella with self-fluorescence and biodegradability is used in this paper as a template to prepare magnetic Chlorella-based microrobots through magnetron sputtering. The assembly and actuation of large-volume Chlorella swarms are realized using a magnetic tweezer system with a robust magnetic field. Experimental results indicate that the magnetic Chlorella swarms (MCS) possess excellent degradation capability and mobility, enabling automatic navigation in various scenarios. Notably, the MCS successfully moved on the spiral channel containing bovine serum and effectively crossed the simulated channel. Furthermore, in vitro studies of real articular cartilage fragments have revealed the motion capacity of the MCS. This research provides a functional microrobot swarm platform for targeted delivery and precision therapy.