Fig. 2.

Size and shape effects on path length distributions. a We fabricate microstructures with circular, squared and triangular shapes all in four different sizes varying by an overall factor of 4 (the scalebar is 20 μm). The density of obstacles is the same for all structures. Bacterial trajectories are plotted over microstructure images that have been processed for contrast enhancement. Trajectories are color coded according to their scaled length (see colorbar). b Bar plots are the experimental distributions of scaled path lengths for each of the structures in a. The black points represent the mean scaled path length and the errorbar the corresponding standard deviation. Lines are theoretical distributions obtained by the numerical simulation of a Lorentz gas model with anisotropic obstacles mimicking experimental conditions