Figure 2

Preparation of Micrometric Suspended F8BT Membrane Lattices on Open-Ended Pass-Through Micropipes. (a) Sketch showing the phases of membrane formation in silicon microstructured templates featuring both closed-ended and open-ended pass-through micropipes leading to suspended membrane formation only on these latter (positive control samples): (a-1) polymer infiltration pattern resulting from drop-casting deposition of 10 μL of polymer solution with 1 wt% of F8BT onto silicon microstructured templates featuring a 2D array of both closed-ended and open-ended pass-through micropipes, also highlighting the stop-valve mechanism taking place in open-ended pass-through micropipes and the complete filling of closed-ended micropipes, (a-2) formation of a continuous polymer layer on top of the silicon microstructured template upon solvent evaporation from the solution on top of the template, (a-3) solvent evaporation causing flow menisci either to move downward in closed-ended micropipes or to move backward in open-ended pass-through micropipes, (a-4) suspended polymer membrane formation at the inlet of open-ended pass-through micropipes and thick polymer layer deposited at the bottom of closed-ended micropipes upon full solvent evaporation. (b–e) Bright-field (b,d) and fluorescence (c,e) optical top view images acquired in the area with open-ended pass-through micropipes (b,c) and at the boundary between open-ended pass-through micropipes (right) and closed-ended micropipes (left) (d,e) showing suspended F8BT membranes formed at the inlet of open-ended pass-through micropipes after drop-casting deposition of 10 μL of polymer solution with 1 wt% of F8BT onto a silicon template as sketched in (a).