Image guided steering of a magnetically coated swimmer with Magnetic Particle Imaging

Magnetic actuation is of great interest for the local delivery of therapeutics towards regions which are difficult to access. A 3D printed swimmer, which is coated with magnetic nanoparticles was developed. This swimmer of mm-size can be used as an untethered transporter through the vascular system. The steerability as well as the simultaneous visualization of the swimmer is demonstrated by using magnetic particle imaging (MPI). MPI is a very promising imaging technique, because it enables three-dimensional real-time imaging of magnetic nanoparticles without ionizing radiation. It is highly beneficial for the combination with magnetic actuation, since the magnetic fields of MPI scanners cannot only be used for the image acquisition but for magnetic actuation as well. The steerability of the swimmer in a vessel phantom is demonstrated and MPI images of the moving swimmer are shown.