Exploratory design in medical nanotechnology: a mechanical artificial red cell.

Molecular manufacturing promises precise control of matter at the atomic and molecular level, allowing the construction of micron-scale machines comprised of nanometer-scale components. Medical nanomachines will be among the earliest applications. The artificial red blood cell or "respirocyte" proposed here is a bloodborne spherical 1-micron diamondoid 1000-atm pressure vessel with active pumping powered by endogenous serum glucose, able to deliver 236 times more oxygen to the tissues per unit volume than natural red cells and to manage carbonic acidity. An onboard nanocomputer and numerous chemical and pressure sensors enable complex device behaviors remotely reprogrammable by the physician via externally applied acoustic signals.