Motion characteristics and control of magnetic microbeads by magnetic gradient fields

The research of micro and nano robots become popular due to their abilities of minimally invasive surgery and target therapy. However, the micro-operation will be limited since a uniform magnetic field cannot generate magnetic force act on target and the magnetic field strength and gradient are not large enough to offer great operability. In this paper, a magnetic system is used as the power source of magnetic object. The magnetic system consist of coils and soft magnetic core, which can generate large gradient magnetic field. This gradient magnetic field can be calculated by liner superposition of multi magnetic coils. Simulation result shows that this system has outstanding micro-operation capability. The velocities of the microbeads under gradient magnetic field generated by different currents are measured and the velocity increases with the current. The microbeads achieve following the predefined path in trajectory control experiments, which demonstrate good operability at the micro-scale. In the future work, in vivo experiments targeted tumor therapy will be studied.