Fig. 5.

The trajectory of particles with different diameters and corresponding recurrence maps. (A and B) Particle trajectories inside a unit cell with different particle diameters. Here, the particle diameters are $D_p=20\mathit{\text{,}}45nm$, respectively, and $N_p=10$, $D_0=240nm$ and $D_x=D_y=400nm$. A black circle represents the particle with a given radius. (C and D) Corresponding recurrence maps for a particle starting at the midpoint (${\eta }_0=0.5$). The dark gray regions represent a forbidden region by the particle–wall interaction as directional locking. The black circle shows the particle radius with a scale of gap size. (E) The critical diameter dependence on the pillar geometry ($D_0/D_y$). (F) The effect of DLD array geometry on the transition from altered zigzag to bumping mode. The plot shows the normalized migration angle as a function of particle size for different pillar diameter ($D_0/D_y$). The simulated particle diameters $D_p$ range from 1 to 110 nm, and the pillar diameters $D_0$ are $80\mathit{\text{,}}120\mathit{\text{,}}160\mathit{\text{,}}200\mathit{\text{,}}240\mathit{\text{,}}280nm$. The dotted lines represent the critical diameter calculated from E.