electroformation of giant phospholipid vesicles on a silicon substrate advantages of controllable surface properties we introduce the use of silicon si as a substrate for the electroformation of giant phospholipid vesicles by taking advantage of the tunability of silicon surface properties we varied the organization of the phospholipid film on the electrode and studied the consequences on vesicle formation in particular we investigated the effects of si surface chemistry and microtopology on the organization of the phospholipid film and the properties of the final vesicles we established correlations between chemical homogeneity film defects and resulting vesicle size distribution by considering phospholipid films that are artificially fragmented by electrode microstructures we showed that the characteristic size of vesicles decreases with a decrease in microstructure dimensions we finally proposed a way to control the vesicle size distribution by using a micropatterned silicon dioxide layer on a si substrate