  Bilayer membranes self-assembled from simple amphiphiles in solution always
have a planar ground-state shape. This is a consequence of several internal
relaxation mechanisms of the membrane and prevents the straightforward control
of vesicle size. Here, we show that this principle can be circumvented and that
direct size control by molecular design is a realistic possibility. Using
coarse-grained calculations, we design tetrablock copolymers that form
membranes with a preferred curvature, and demonstrate how to form
low-polydispersity vesicles while suppressing micellization.
