Analysis and optimal design of magnetic navigation system using helmholtz and maxwell coils

The Helmholtz coils combined with the Maxwell coils can be used to generate the magnetic force for navigating a permanent magnet microrobot in the desired direction. To manipulate the microrobot effectively, two points should be noted: 1) High magnetic field uniformity of Helmholtz coils and magnetic field gradient uniformity of Maxwell coils; 2) High magnetic force with less current which reduces coil-heating and power consumption. Considering the two points, we evaluate and optimize the magnetic propulsion system in this paper. Firstly, two perpendicular Maxwell coils are presented to generate gradient magnetic field with theoretical analysis. The results indicate the two pairs of Maxwell coils system has better electrical properties than one pair. Secondly, we optimize the Helmholtz and Maxwell coils for the uniformities with considering coil thickness. The proposed system for the microrobot has higher navigation accuracy and good electrical properties.