Abstract: The disclosed embodiments provide a system that performs molecular assembly. During operation, the system delivers one or more droplets of a fluid onto a surface using a nanofluidic delivery probe and an associated high-precision positioning device, wherein the solution comprises a solvent and one or more solute molecules, and wherein delivery of the droplets onto the surface facilitates evaporation-driven assembly of one or more structures on the surface. Moreover, while delivering a droplet onto the surface, the system controls a size of the droplet and a shape of the droplet during evaporation to produce a variety of shapes in resulting structures.