Nanotechnological proposal of RBC Molecular manufacturing promises precise control of matter at the atomic and molecular level. One major implication of this realization is that in the next 10-30 years it may become possible to construct machines on the micron scale, comprised of parts on the nanometer scale. Subassemblies of such devices may include such useful robotic components as 100-nm manipulator arms, 400-nm mechanical GHz-clock computers, 10-nm sorting rotors for molecule-by-molecule reagent purification, and smooth superhard surfaces made of atomically flawless diamond. Such technology has clear medical implications. It would allow physicians to perform precise interventions at the cellular and molecular level. Medical nanorobots have been proposed for gerontological applications, in pharmaceutical research, and to diagnose diseases ,mechanically reverse atherosclerosis, supplement the immune system, rewrite DNA sequences in vivo, repair brain damage, and reverse cellular insults caused by "irreversible" processes or by cryogenic storage of biological tissues. The goal of the present paper is to present one such preliminary design for a specific medical nanodevice that would achieve a useful result: An artificial mechanical erythrocyte (red blood cell, RBC), or "respirocyte."