Figure 1: Design and principle of the experiment.

(a) Sketch of the experimental setup, including a container for cell suspension placed on an orbital mixer (i) to keep the cell concentration uniform, a peristaltic pump (ii), the microfluidic production device (iii), and tubing. The microfuidic device consists in a large entrance compartment, distributing the suspension among sixteen straight channels, whose serpentine shape allows the design to fit in a single glass slide. Each of these channels is wide, deep and long. The dark blue region corresponds to the pillar forests that cover the straight part of the channels, while the U-turns are devoid of obstacles. (b) Pillars are arranged on a tilted hexagonal lattice. The angle between the main axis of the channel and that of the lattice is fixed to 10° in order to ensure that each cell encounters at least one pillar. The streamlines are illustrated with black lines and MKs with orange spheres. (c) Top view of the micro pillar array before cell perfusion and after 60 minutes perfusion. The capture process of cells at intermediate times will be described in Fig. 2. Scale bar, 100 m.