Design of a Miniaturized Magnetic Actuation System for Motion Control of Micro/Nano Swimming Robots

Magnetically controlled microrobots for drug delivery and noninvasive treatment have great potential applications in the biomedical field in the future. The construction of the magnetic actuation system is an important step to realize the automated control of micro/nano swimmers. However, the construction of a magnetic actuation system still faces challenges; for example, the magnetic field cannot be turned off immediately, the distribution of the magnetic field in the workspace is not uniform, the working space is limited and the feedback is inconvenient. In view of the above problems, a design method based on an eight-axis electromagnetic coil magnetic control system is introduced in this paper, which can compositely actuate the microrobot and ensure movement with five degrees of freedom. In addition, the overall size of the system can be reduced as much as possible under the condition that the magnetic field in the workspace is sufficiently uniform and the magnetic field intensity is sufficiently large. Finally, in the experimental part, the magnetic field uniformity is verified by magnetic field simulation and measurement, and then the path following of the square trajectory is realized with the $75 \mu \mathrm{m}$ helical microswimmer as the operating object.