Nanofibers are formed using electrospray deposition from microfluidic source. The source is brought close to a surface, and scanned in one embodiment to form oriented or patterned fibers. In one embodiment, the surface has features, such as trenches on a silicon wafer. In further embodiments, the surface is rotated to form patterned nanofibers, such as polymer nanofibers. The nanofibers may be used as a mask to create features, and as a sacrificial layer to create nanochannels.