Position-Amplified Particle Manipulation and Targeted Placement Using Magnetic Levitation with Moving Dual-Ring Permanent Magnets

Label-free and non-contact manipulation methods capable of actively regulating particle trajectories are important for particle handling, selective separation, and targeted collection. However, conventional magnetic-levitation approaches primarily rely on passive equilibrium positioning and provide limited capability for actively transporting particles to prescribed locations. Here, we propose a position-amplified active MagLev method that uses a moving magnetic field as a controllable non-contact actuator for particle manipulation, separation, and targeted placement. A magneto-manipulation model incorporating gravity, buoyancy, magnetic force, and hydrodynamic drag is established to predict particle trajectories and the final center distance, enabling parameter optimization. For particles of the same density with diameters of 3, 4, and 5 mm, the predicted horizontal center-to-center distances between the 3 and 4 mm particles and between the 4 and 5 mm particles are 13.16 and 3.40 mm, respectively, closely matching experimental values of 12.46 and 3.56 mm (deviations of 0.70 and 0.16 mm, respectively). The three particles form a size-ordered spatial distribution and are successfully directed into separate collection troughs. Vertically, increasing magnet spacing enhances vertical density sensitivity and enlarges inter-material distances; for TPEE, PA66, and PC/ABS, the vertical distance between PA66 and TPEE increases from 3.99 mm to 5.70 mm, and that between PA66 and PC/ABS increases from 3.08 mm to 3.99 mm, with all three guided into distinct troughs. These results demonstrate that the proposed method extends MagLev from passive equilibrium positioning to an active, model-guided manipulation platform in which particle-property differences are converted into predictable spatial responses and subsequently exploited for targeted collection. The method therefore integrates non-contact transport, positional separation, sensitivity tuning, and prescribed particle placement within a single magnetic-manipulation process.