Liquids are usually described within classical physics, whereas solids require the tools of quantum mechanics. I will show that in nanoscale channels this distinction no longer holds. At these scales, the liquid flows become intertwined with electron dynamics in the channel walls, resulting in a wealth of phenomena beyond the reach classical fluid mechanics. I will discuss the quantum friction effect, which controls the water permeability of carbon nanotubes, and the generation of electric current through hydrodynamic Coulomb drag. My research explores these phenomena as new design principles for energy conversion and molecular separation processes.