The fabrication of nanoscale structures with dimensions approaching the scale of biological molecules offers approaches to the study of fluid dynamics and biomolecular transport. Ultimately, a parallel lithographic approach will be necessary if devices based on these nanofluidics are to achieve widespread availability and acceptance. We report on a flexible, all-optical lithography alternative that is amenable to,large-scale production. We use interferometric lithography (IL) and anisotropic etching to produce large areas of parallel, nanofluidic channels with widths of similar to 100 mn and depths of up to 500 nm. We also use standard optical lithography to create interfacing microchannels, such that the range of spatial scales on one chip varies by 104 (from mm scale reservoirs to 100 nm nanochannels). We provide initial demonstrations of capillary action and electrophoretic motion of fluorescent dye solutions. (C) 2003 American Vacuum Society.