I'm not sure why people seem so convinced that MNT is a hard requirement here. To be sure there are some components that require fine micrometer to nanometer level precision, but existing mechanical and/or chemical approaches do work, otherwise we wouldn't have things like computer chips
You can draw fibers, use cantilevers, exploit the wavelength properties of laser light, electromagnetically control the path of ionized materials in a vacuum, use piezoelectric actuators that convert current to angstrom level movements, and so on. Not to mention the many approaches to coating a surface with a very thin layer: vacuum deposition, spin coating, electroplating, etc.
You can draw fibers, use cantilevers, exploit the wavelength properties of laser light, electromagnetically control the path of ionized materials in a vacuum, use piezoelectric actuators that convert current to angstrom level movements, and so on. Not to mention the many approaches to coating a surface with a very thin layer: vacuum deposition, spin coating, electroplating, etc.