Nanorobots in Your Future

An exciting revolution in health care and medical technology looms large on the horizon. Yet the agent of change is microscopically small, and will be made possible by nanotechnology. Nanotechnology is the engineering of molecularly precise structures and, ultimately, molecular machines. The prefix nano- refers to the scale of these constructions. A nanometer is one-billionth of a meter, the width of about 5 carbon atoms nestled side by side. Nanomedicine is the application of nanotechnology to medicine. The ultimate tool of nanomedicine is the medical nanorobot “ a robot the size of a bacterium, composed of molecule-size parts somewhat resembling macroscale gears, bearings, and ratchets.

The first and most famous scientist to voice the possibility of nanorobots traveling through the body, searching out and clearing up diseases, was the late Nobel physicist Richard P. Feynman. In his remarkably prescient 1959 talk Theres Plenty of Room at the Bottom, Feynman proposed employing machine tools to make smaller machine tools, these to be used in turn to make still smaller machine tools, and so on all the way down to the atomic level, noting that this is a development which I think cannot be avoided.

With these small machine tools in hand, small mechanical devices, including nanorobots, could be constructed. This technology, said Feynman, suggests a very interesting possibility for relatively small machines. Although it is a very wild idea, it would be interesting in surgery if you could swallow the surgeon. You put the mechanical surgeon inside the blood vessel and it goes into the heart and looks around. (Of course the information has to be fed out.) It finds out which valve is the faulty one and takes a little knife and slices it out. …[Imagine] that we can manufacture an object that maneuvers at that level!… Other small machines might be permanently incorporated in the body to assist some inadequately functioning organ.

We cannot build such tiny robots today. But perhaps by the late 2020s or early 2030s, we will. These future devices may be made of rigid diamondoid nanometer-scale parts and subsystems including onboard sensors, motors, manipulators, and molecular computers. They will be fabricated in a nanofactory via positional assembly: picking and placing molecular parts one by one, then moving them along controlled trajectories much like the robot arms that manufacture cars on automobile assembly lines. These steps are repeated over and over with all the different parts until the final product, such as a medical nanorobot, is fully assembled.

The ability to build nanorobots cheaply and in therapeutically useful numbers would revolutionize the practice of medicine. Performance improvements up to 1000-fold over natural biological systems of similar function appear possible. For example, the respirocyte is an artificial mechanical red blood cell just 1 micron in diameter having 1/100th the volume of a natural red cell. Red cells carry oxygen to our tissues and remove carbon dioxide. Respirocytes do too, but would be made of much stronger diamond-like materials, not floppy lipids and proteins as we find in living cells. This allows respiratory gases to be safely stored within the respirocyte at tremendous pressures “ up to 1000 atmospheres “ and to be loaded or unloaded, molecule by molecule, using mechanical pumps on the devices surface. This simple nanorobot is regulated by onboard computers, powered by glucose fuel cells, and controlled by a physician who communicates with the device via ultrasound signals beamed into the body from outside. A therapeutic 5-cc injection of respirocytes, just 1/1000th of total blood volume, duplicates the oxygen-carrying ability of the entire human blood mass and could instantly revive emergency victims of carbon monoxide poisoning at the scene of a fire.

Artificial mechanical white blood cells called microbivores are nanorobots that would seek and digest harmful bloodborne pathogens including bacteria, viruses, or fungi. The pathogens are completely digested into harmless sugars, amino acids and the like, which are the only effluents from this 3-micron nanorobot. No matter that a bacterium has acquired multiple drug resistance to antibiotics or to any other traditional treatment “ the microbivore will eat it anyway. Microbivores would completely clear even the most severe bloodborne infections in hours or less, then be removed from the body. This is 1000 times faster than the weeks or months often needed for antibiotic-based cures. Related medical nanorobots with enhanced tissue mobility could similarly consume tumor cells with unmatched speed and surgical precision, eliminating cancer. Other devices could be programmed to remove circulatory obstructions in just minutes, quickly rescuing even the most compromised stroke victim from near-certain brain damage.

Nanorobots could perform surgery on individual cells. In one procedure, a nanorobot called a chromallocyte, controlled by a physician, would extract existing chromosomes from a diseased cell and insert fresh new ones in their place. This process is called chromosome replacement therapy. The replacement chromosomes are manufactured earlier, outside of the patients body, by a desktop nanofactory that includes a molecular assembly line, using the patients individual genome as the blueprint. If the patient chooses, inherited defective genes could be replaced with nondefective base-pair sequences, permanently curing any genetic disease and permitting cancerous cells to be reprogrammed to a healthy state. Each chromallocyte is loaded with a single copy of the digitally-corrected chromosome set. After injection, each device travels to its target tissue cell, enters the nucleus, replaces old worn-out genes with new chromosome copies, then exits the cell and is removed from the body.

The implications for extension of healthy lifespan are profound. Perhaps most importantly, chromosome replacement therapy could be used to correct the accumulating genetic damage and mutations that leads to aging in every one of your cells. With annual checkups and cleanouts, and some occasional major cellular repairs, your biological age could be restored once a year to a more or less constant physiological age that you select. Nanomedicine thus may permit us first to arrest, and later to reverse, the biological effects of aging and most of the current medical causes of natural death, severing forever the link between calendar time and biological health.

Website References

1. Personal website of Robert A. Freitas Jr.

2. Nanomedicine website

3. Nanofactory Collaboration website

4. Nanomedicine Art Gallery

Literature References (technical)

1. First book on nanomedicine ever published: Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999. URL:

2. First medical nanorobot design paper ever published (respirocytes): Robert A. Freitas Jr., Exploratory Design in Medical Nanotechnology: A Mechanical Artificial Red Cell, Artificial Cells, Blood Substitutes, and Immobil. Biotech. 26(1998):411-430. URL:

3. Published design paper on the microbivores: Robert A. Freitas Jr., Microbivores: Artificial Mechanical Phagocytes using Digest and Discharge Protocol, J. Evol. Technol. 14(April 2005):55-106.

4. First technical description of a cell repair nanorobot ever published: Robert A. Freitas Jr., The ideal gene delivery vector: chromallocytes, cell repair nanorobots for chromosome replacement therapy, J. Evol. Technol. 16(June 2007):1-97.

5. Survey book on self-replication: Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004. URL:

6. Best survey of future nanorobot applications in medicine: Robert A. Freitas Jr., Chapter 23. Comprehensive Nanorobotic Control of Human Morbidity and Aging, in Gregory M. Fahy, Michael D. West, L. Stephen Coles, and Steven B. Harris, eds, The Future of Aging: Pathways to Human Life Extension, Springer, New York, 2010, pp. 685-805.

Literature References (popular)

1. Robert A. Freitas Jr., Say Ah! The Sciences 40(July/August 2000):26-31. URL:

2. Robert A. Freitas Jr., Death is an Outrage! Invited Lecture delivered at the Fifth Alcor Conference on Extreme Life Extension, 16 November 2002, Newport Beach, CA. URL:

3. Robert A. Freitas Jr., Nanomedicine,, 17 November 2003. URL:

2011 Robert A. Freitas Jr. All Rights Reserved.

By Robert A. Freitas Jr., J.D.

Robert A. Freitas Jr. is Senior Research Fellow at the Institute for Molecular Manufacturing (IMM) in Palo Alto, California, and was a Research Scientist at Zyvex Corp. (Richardson, Texas), the first molecular nanotechnology company, during 2000-2004. He received B.S. degrees in Physics and Psychology from Harvey Mudd College in 1974 and a J.D. from University of Santa Clara in 1979. Freitas co-edited the 1980 NASA feasibility analysis of self-replicating space factories and in 1996 authored the first detailed technical design study of a medical nanorobot ever published in a peer-reviewed mainstream biomedical journal. Freitas is the author of Nanomedicine, the first book-length technical discussion of the potential medical applications of molecular nanotechnology; the initial two volumes of this 4-volume series were published in 1999 and 2003 by Landes Bioscience. His research interests include: nanomedicine, medical nanorobotics design, molecular machine systems, diamondoid mechanosynthesis (theory and experimental pathways), molecular assemblers and nanofactories, atomically precise manufacturing, and self-replication in machine and factory systems. He has published 49 refereed journal publications and contributed book chapters, co-authored Kinematic Self-Replicating Machines (Landes Bioscience, 2004), and in 2006 co-founded the Nanofactory Collaboration. He won the 2009 Feynman Prize in nanotechnology for theory, the 2007 Foresight Prize in Communication, and the 2006 Guardian Award from Lifeboat Foundation. He wrote the first two U.S. patents ever filed on diamond mechanosynthesis (the first of which was awarded on 30 March 2010) and serves on the Editorial Boards of 9 medical or nanotech journals. His home page is