MICROBIVORES - ARTIFICIAL WHITE BLOOD CELLS:
NANOROBOTIC PHAGOCYTES"Microbivore" is the name given to a speculative future micromachine containing numerous nanomachine systems, which function together as an artificial phagocyte (white blood cell.) A fleet of microbivores could be injected into a person and act as a supplement or even a complete replacement for their immune system. The microbivore concept was invented by Robert A. Freitas Jr., who has outlined their design in great detail. At present (2010) we lack the "atom-by-atom" molecular manufacturing technology required to construct such a device. Some futurists expect the dream of molecular nanotechnology (first concieved by Dr. Eric Drexler) to become a reality sometime next decade, (2020-2030) enabling a massive leap forward in our construction capabilities.
Numerous pathologies exist that are caused by the presence of foreign organisms in the bloodstream. Infection by foreign blood-borne organisms is especially dangerous in individuals with compromised immune systems (such as those suffering from AIDS.) Current methods to control such organisms are largely ineffectual, or merely temporarily arrest their growth rather than wiping them out entirely. Most physicians would welcome the addition of syntheitc nanorobots capable of selectively annihilating such organisms.
The microbivore design calls for a 3.4 micron (millionths of a meter) long, by 2 micron wide oblate spheroid shaped device, consisting of 610 billion structural atoms, and filled with roughly 150 billion gas/water molecules. The entire nanobot has a gross geometric volume of just over 12.1 cubic microns (including two normally empty internal materials processing bays totalling 4 cubic microns of displaced volume.) Its size ensures unobstructed passage through even the narrowest of human capillaries, which are approximately 4 microns in diameter. A single microbivore will consume 100-200 picowatts of continuous power while in operation, and will digest and eliminate pathogenic microbes at a maximum throughput of 2 cubic microns per 30 second cycle - enough room to internalize virtually any species of bacteria in a single gulp. The design includes 10-fold renundancy on most mechanisms, excepting the largest structural elements, to ensure high reliability.
As with natural phagocytes, microbivores would devour, digest, and discharge any viruses, bacteria or fungi unlucky enough to be detected. The microbivore would use species-specific reversible binding sites to firmly attach itself to the microbe, which would then be directed to the ingestion port by telescoping robotic grapples in a similar fashion to the way a squid uses its tentacles to catch and hold its prey while consuming it. From the ingestion chamber, the targetted microbe would be blended by mechanical blades in a morcellation chamber, then passed to a digestion chamber where the processed remains of the invader would be chemically analyzed before being further broken down by a specifically selected sequence of 40 engineered enzymes, into biologically neutral effluent (mononucleotides, amino acids, free fatty acids, simple sugars and glycerol.) which would be released harmlessly back into the bloodstream through an exhaust port on the back of the device, where it could be used by the body's molecular machinery (cells) for its nutritional content.
Getting microbivores into the body would be a matter of simply introducing them intravenously. Preliminary estimates suggest microbivores would be around 80 times more efficient, and about 1,000 times faster acting than our natural white blood cells. Once their mission is complete they could be programmed to exit the bloodstream via the intestines, if desired. Clinical use of microbivores, and the many other species of nanobots thus far imagined, could revolutionize the field of medicine. Mass fabrication and theraputic use of such devices (thanks to molecular nanotech) over the coming decades will lead to cures for many diseases, barring any unforseen insurmountable technical challenges, for many people alive today.
For a more detailed analysis of the microbivore, see: Artificial Mechanical Phagocytes using Digest and Discharge Protocol.