Respirocyte

Respirocytes are hypothetical, microscopic, artificial red blood cells that can emulate the function of its organic counterpart, only with 200 times the efficiency, so as to supplement or replace the function of much of the human body's normal respiratory system. Still entirely theoretical, respirocytes would measure 1 micrometer in diameter. In the original paper by Robert Freitas, titled, "A Mechanical Artificial Red Blood Cell: Exploratory Design in Medical Nanotechnology" (1998), it was proposed that respirocytes would mimic the action of the natural hemoglobin-filled red blood cells. The proposed design of the spherical nanorobot is made up of 18 billion atoms arranged as a tiny pressure tank, which would be filled up with oxygen and carbon dioxide, making one complete transfer point at the lungs, and the reverse transfer at the body's tissues.