Wireless motion control of paramagnetic microparticles using a magnetic-based robotic system with an open-configuration

In this work, motion control of paramagnetic microparticles is achieved using a magnetic system with an open-configuration. This control is done using a permanent magnet and an electromagnetic coil under microscopic guidance. The permanent magnet and the electromagnetic coils are fixed to the end-effector of a robotic arm with 4 degrees-of-freedom to control the motion of the microparticles in three-dimensional (3D) space. A closed-loop control of the robotic arm is done at the joint-space to orient the magnetic field gradients of the permanent magnet and the electromagnetic coil towards a reference point in 3D space. Point-to-point motion control is achieved at an average speed of 117 εm/s using the permanent magnet and the robotic arm, whereas the electromagnetic coil and the robotic arm achieve average speed of 46 εm/s. In addition, the permanent magnet and the robotic arm achieves maximum position error of 600 εm, in the steady-state, as opposed to 100 εm for the electromagnetic coil and the robotic arm. We also demonstrate experimentally that our control system moves the microparticles towards a reference position in the presence of a constrain on the motion of the end-effector. The precise motion control of paramagnetic microparticles using a magnetic system with open-configuration provides broad possibilities in targeted therapy and biomedical applications that cannot be achieved using magnetic systems with closed-configurations.