The 3D navigation system of micro-nano robot based on magnetic particle imaging is a promising technique to be used for targeted drug delivery. Using the magnetic actuator by manipulating field free point (FFP) and non-invasive molecular imaging method such magnetic particle imaging, the device can reduce the harm in treatment. In this paper, we used closed-loop control to steer a micro robot to a desired position by a 3D FFP magnetic force based system. A custom-built MPI system with a bore size of 90 mm that can generate a gradient as high as 4T/m/µ0 was used to verify the control system in three dimensions
