Figure 4.

(a) Biofilm streamers that developed after 18 h of continuous flow, from left to right, at 0.5 μl min⁻¹ (OD₆₀₀$=0.25$). The confocal image sequences on the left and right sides were obtained from the bottom and mid-horizontal planes of the channel, respectively, for all of the curved sections shown in Fig. 2. Scale bars: 200 μm. (b) Average diameter of the streamers after ∼14 h of continuous flow versus α_fl for different flow rates, i.e., 0.5 μl min⁻¹$\left(\mathrm{▾}\right)$, 1 μl min⁻¹$\left(\mathrm{■}\right)$, and 1.5 μl min⁻¹$\left(\mathrm{▴}\right)$.