Figure 2.

Trajectories of beads with a 1 cm × 1 cm × 2 cm external permanent magnet at different positions in simulation 1(a–c), bar = 600 μm. All the beads (a), part of the beads (b), and few beads (c) deflected to the wall of the branched channel with 𝑢_𝑓𝑙 = 120 uL/h; (a) x = 1 mm, (b) x = 4 mm, and (c) x = 7 mm. (d) Distance between final position of beads at different flow velocities and magnet positions in simulation and experiment. (e) The time of beads crossed the main channel with different conditions in simulation 1.