Design and Simulation of a Magnetization Drive Coil Based on the Helmholtz Principle and an Experimental Study

In order to realize the magnetization of hydrogel mixed with NdFeB powder, a magnetization drive coil based on a Helmholtz coil is designed in this paper. The 3D model of the magnetic field system is drawn by the Maxwell software 3D module, and the influence of different factors on the magnetic induction intensity is analyzed to obtain the optimized structure of the magnetization drive coil; then, the central magnetic induction intensity and magnetic induction line distribution density of the magnetization drive coil and Helmholtz coil are compared to verify the reliability of the structure optimization. The results show that the central magnetic induction intensity is the highest when the distance between the auxiliary coils is 70 mm, the central magnetic induction intensity of the magnetized drive coil is significantly higher than that of the Helmholtz coil when the number of turns is the same, and the central magnetic induction intensity of the optimized magnetized drive coil can reach 1.37 T with a more uniform and dense magnetic induction line distribution. After building the magnetization drive coil, the magnetic induction intensity of the center of the magnetization drive coil can reach 1.34 T by a handheld digital Gauss meter test, and the error is no more than 2% with the simulation result. This design approach provides a reference for the structural design and operating characteristics analysis of magnetized drive coils and shortens the design cost and development cycle of magnetized drive coils.