Microscopic Folds and Macroscopic Jerks in Compressed Lipid Monolayers

We report hitherto unrecognized cooperative behavior in the stochastic collapse of certain compressed lipid
monolayers implicated in pulmonary function. The cooperativity emerges from a statistical analysis of the
collapse events captured using fluorescence microscopy and digital image analysis. The collapse events involve
folding of the monolayer on a micron scale, yet each event produces a macroscopic jerk of the layer. The
cooperative collapse is striking for its temporal sharpness and large spatial extent.