Septins are a conserved family of GTPase proteins, found from yeast to humans, that assemble into filaments and rings. They play essential roles in cell division, polarity, and the maintenance of membrane organization, particularly at intercellular bridges during cytokinesis. In this seminar, I will present bottom-up in vitro reconstitution approaches developed with septins. Using various model membrane systems, I will show that septins are sensitive to micrometric curvatures, a particularly unusual behavior, as the vast majority of curvature sensing proteins recognize nanometric curvatures! I will then present results demonstrating that septins can act as lateral diffusion barriers within membranes. Finally, I will share preliminary results on the reconstitution of intercellular bridges in microfluidics, opening new perspectives for studying cytokinesis in a controlled environment.