Closed-Loop Control for a Heterogeneous Group of Magnetically-Actuated Microrobots

The development of magnetically-actuated microrobots is of great interest for emerging medical applications due to their inherent safety, low cost to manufacture, and flexibility. In many practical applications, precise control over the motion of the microrobots is a strong requirement. In these contexts, closed-loop control is a practical tool to adjust the microrobots' control inputs in real time. In this work, we describe a process to quickly fabricate a large number of heterogeneous microrobots using colloidal synthesis. We simultaneously develop a closed-loop control law that drives the microrobots to a desired formation in the plane. In addition, we prove that heterogeneity in the microrobot dynamics is necessary to generate arbitrary formations. Finally, using experimental data, we show in simulation that $N=4$ microrobots can be driven to any arbitrary formation using our control law.