FIG. 4.

Fluorescent imaging of flow inside the L₃ cavity connected to channels with $W_{ch}=30\hspace{0.17em}\mu$m (a)–(c), $40\mu$ m (d)–(f), and $50\hspace{0.17em}\mu$m (g)–(i) at different Re using $d=1\hspace{0.17em}\mu$m tracers. Considering the difference in hydraulic diameter, the flow rates required to generate a specific Re in a wider channel is larger. Regardless of the difference between W_ch, the morphology of vortices is almost similar at identical Re. (a) W_ch = 30 μm, Re = 63, (b) W_ch = 30 μm, Re = 123, (c) W_ch = 30 μm, Re = 216, (d) W_ch = 40 μm, Re = 63, (e) W_ch = 40 μm, Re = 123, (f) W_ch = 40 μm, Re = 216, (g) W_ch = 50 μm, Re = 63, (h) W_ch = 50 μm, Re = 123, and (i) W_ch = 50 μm, Re = 216.