2.4 Biofilm deformation experiments
The synthetic biofilm or homogenized P. aeruginosa biofilm was
inserted into a cylindrical support with a dimension of 1mm × 3mm
(diameter × height) (Fig. 2). The biofilm cylinder-shaped support was
glued inside a flow cell with a dimension of 25 cm × 10 mm × 10 mm
(length × width × height). The flow was driven by gravity, and the flow
rate was controlled with a valve on the influent line. The large size of
the water reservoir and the short duration of the experiment led to
minimal changes in water level in the water reservoir, therefore
providing near-constant velocities. The flow rate (\(u_{1}\)) was
measured by directing the effluent to a graduated cylinder. Biofilm
morphologies were monitored and recorded using optical coherence
tomography (OCT) (Ganymede II, Thorlabs GmbH, Lübeck, Germany). The
image collection software was ThorImage OCT, Version 5.0.1. The
cross-sectional images of biofilm were captured by recording a real-time
video of the OCT output (SI V1-V2).