Movement characteristics evaluation of the spherical robot actuated by the magnetic field for medical applications

The capsule microrobot will play an important role in the medical application such as the minimally invasive surgery in the future. In this paper, we proposed the spherical capsule robot system driven by the external magnetic field. And then we did the finite element analysis of the electromagnetic device involved in the system using ANSYS software. In the end, to verify our analysis results and establish relationship with the experimental system, we conducted the comparison between experimental results and theoretical results. In addition, the spherical robot motion was also recorded in the tube and an open plastic sink. Combining with the proposed experimental platform, we can change the orientation of the capsule robot by changing the direction of the external magnetic field and change the moving speed by changing the frequency of the external magnetic field. The driving force of the Helmholtz coil on the capsule robot can be generated along the space any direction by changing the parameters of the input signal in theory. Besides that we found that the variation tendency of the magnetic field is the same between experimental values and simulation results. We can adjust the parameters of the input current on the basis of the simulation results in order to obtain the needed external magnetic field during the actual operation. The capsule robot motion indicated that the capsule robot motion is related to other factors except the external driving force. The experiments in an open plastic cup indicated that the spherical capsule robot can actively motion along the predetermined direction in the plane. The research results in this paper will provide the strong supports for actuating the capsule robot with the external magnetic field for medical applications in the future.