Analytical and numerical analysis of magnetic propulsion force of a cylindrical micro-robot considering the characteristics of magnetic material

Abstract

This paper analytically calculates the magnetic propulsion force of the cylindrical micro-robot using permanent magnetic material and soft magnetic material operated under the Helmholtz and the Maxwell coils. And the analytical results of magnetic force are compared with those by the finite element method. It shows that the proposed analytical method predicts the magnetic force accurately. It also shows that the pre-existing magnetization of permanent magnetic material of a micro-robot generates much bigger magnetic propulsion force than that of soft magnetic material. The micro-robot with soft magnetic material always needs the Helmholtz coil to generate the magnetization of soft magnetic material. This may make the motion control of a micro-robot with soft magnetic material complicated, because the Helmholtz coil affects the magnetic force and magnetic torque of soft magnetic material at the same time.