Fig. 1.

The passage of a long air bubble creates a characteristic pattern of holes in a biofilm. a Schematic of the microfluidic setup showing the geometry of the microchannel and the experimental method, in which P. aeruginosa bacteria preferentially attached to hydrophobic patches. After a specified growth time (4 h, 8 h, or 12 h), a controlled air bubble was injected in the channel at a mean flow speed of 250 µm s⁻¹. b Residual biofilm after the passage of the bubble, revealing a semi-regular pattern of holes formed in an 8 h-old biofilm, for different initial patch sizes (measuring 400² μm², 300² μm², 200² μm², and 100² μm²). Scale bars, 50 µm