Enhanced Locomotion of Protein-Based Microrobots via Magnetic Assemblies * .

Magnetic microrobots are promising for biomedical applications in living organisms, thanks to their remote actuation and non-contact manipulation capabilities. However, controlling single microrobots one after another is technically inefficient. Previous studies showed swarm control of microrobots. Here we introduce a more direct strategy for enhancing the transport efficiency of microrobots by manipulating their assemblies. We present the control of a protein-based microbead system capable of forming magnetic micro-assemblies. By using rotating magnetic fields, we effectively realized the rolling motion of single microbeads, paired microbeads, and assemblies of multiple microbeads. Improved transport velocity is achieved by controlling the assembly of the multiple microrobots. The maximum velocity of the magnetic micro-assembly reaches 1014 μm/s, while the single microbead and micro-dimer is 203 μm/s and 726 μm/s, respectively. And the line coincidence of micro-assembly reaches 0.988. Our results highlight the potential of the controlling strategy based on magnetic assemblies for diverse biomedical applications. The direct control of such magnetic assemblies offers a simpler and more biocompatible solution for improving the transport efficiency of microrobots.