Michael Anissimov, at Accelerating Future, nuclear powered nanorobots for replacing food. The concept is briefly described in the Futurist magazine. The Futurist magazine has a solutions page which includes the Freitas work
Here’s how these would work: the only reason people eat is to replace the energy they expend walking around, breathing, living life, etc. Like all creatures, we take energy stored in plant or animal matter. Freitas points out that the isotope gadolinium-148 could provide much of the fuel the body needs. But a person can’t just eat a radioactive chemical and hope to be healthy, instead he or she would ingest the gadolinium in the form of nanorobots. The gadolinium-powered robots would make sure that the person’s body was absorbing the energy safely and consistently. Freitas says the person might still have to take some vitamin or protein supplements but because gadolinium has a half life of 75 years, the person might be able to go for a century or longer without a square meal.
A Len Holmes Presentation on Nanotechnology to a Biochemistry Class in 2005 provided the likely mechanism and function of the nuclear nanobot food replacer. Above is a page that describes ATP synthase.
“Nutribots” floating through the bloodstream would allow people to eat virtually anything, a big fatty steak for instance, and experience very limited weight or cholesterol gain. The nutribots would take the fat, excess iron, and anything else that the eater in question did not want absorbed into his or her body and hold onto it. The body would pass the nurtibots, and the excess fat, normally out of the body in the restroom.
A nanobot Dr. Freitas calls a “lipovore” would act like a microscopic cosmetic surgeon, sucking fat cells out of your body and giving off heat, which the body could convert to energy to eat a bit less.
Where can you read more about Robert Freitas’s ideas? In the January-February 2010 issue of THE FUTURIST magazine, Freitas lays out his ideas for improving human health through nanotechnology.
1. Damian G. Allis, Robert A. Freitas Jr., Ralph C. Merkle, “Single-Atom Radical-Exchange Mechanosynthetic Transfer Reactions for Period 1,2,3,4 Elements using Monosubstituted Adamantane Tools and Workpieces,” J. Comput. Theor. Nanosci. 7(2010). In preparation.
2. Colin Weatherbee, Robert A. Freitas Jr., “Nanoscale Robot Navigation of the Human Kidney,” 2010. In preparation.
3. 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. In press. Publisher’s book website ….. Publisher’s book flyer
4. Denis Tarasov, Natalia Akberova, Ekaterina Izotova, Diana Alisheva, Maksim Astafiev, Robert A. Freitas Jr., “Optimal Tooltip Trajectories in a Hydrogen Abstraction Tool Recharge Reaction Sequence for Positionally Controlled Diamond Mechanosynthesis,” J. Comput. Theor. Nanosci. 6(2009). In press.
5. Tad Hogg, Robert A. Freitas Jr., “Chemical Power for Microscopic Robots in Capillaries,” Nanomedicine: Nanotech. Biol. Med. 5(2009). In press. (Arxiv Preprint)
6. Robert A. Freitas Jr., “Welcome to the Future of Medicine,” Studies in Health Technol. Inform. 149(2009):251-256. PubMed Abstract (HTML) ….. Full Paper (HTML)
This chapter describes the negative consequences of medical technology development and commercialization that is too slow, and makes the case for an immediate large scale investment in medical nanorobots to save 52 million lives a year. It also explains the essence of nanotechnology, its life-saving applications, the engineering challenges, and the possibility of 1000-fold improvement over our current human biological abilities. Every decade that we delay development and commercialization of medical nanorobotics, half a billion people perish who could have been saved.
7. Robert A. Freitas Jr., “Medical Nanorobotics: The Long-Term Goal for Nanomedicine,” in Mark J. Schulz, Vesselin N. Shanov, YeoHeung Yun, eds., Nanomedicine Science and Engineering, Artech House, Norwood MA, 2009, Chapter 14, pp. 367-392. In press.
8. Robert A. Freitas Jr., “Chapter 15. Computational Tasks in Medical Nanorobotics,” in M.M. Eshaghian-Wilner, ed., Bio-inspired and Nano-scale Integrated Computing, John Wiley & Sons, New York, 2009, pp. 391-428. Purchase Hardcover (Amazon) ….. Full Chapter Text (PDF, 5.2 MB)
9. Robert A. Freitas Jr., “Meeting the Challenge of Building Diamondoid Medical Nanorobots,” Intl. J. Robotics Res. 28(April 2009):548-557. (DOI: 10.1177/0278364908100501) IJJR Abstract (HTML) ….. Full Paper (HTML, 1.0 MB)
* The first theoretical design study of a medical nanorobot ever published in a peer-reviewed medical journal (in 1998) described an artificial mechanical red blood cell or ‘‘respirocyte’’ made of 18 billion precisely arranged atoms —a bloodborne, spherical 1-micron diamondoid 1000-atmosphere pressure vessel [1e] 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, controlled by gas concentration sensors and an onboard nanocomputer
* A second theoretical design study of a medical nanorobot describes an artificial mechanical white cell or ‘‘microbivore’’— an oval-shaped device measuring a few microns in size and made of diamond and sapphire—that would seek out and digest unwanted bloodborne pathogens
* Another theoretical design study describes an artificial mechanical platelet or ‘‘clottocyte’’ that would allow complete hemostasis in as little as B1 second, even in moderately large wounds. This response time is on the order of 100–1000 times faster than the natural hemostatic system.
* The chromallocyte is a hypothetical mobile cell-repair nanorobot whose primary purpose is to perform chromosome replacement therapy (CRT)
The technologies that are needed for the atomically precise fabrication of diamondoid nanorobots in macroscale quantities at low cost require the development of a new nanoscale manufacturing technology called positional diamondoid molecular manufacturing, enabling diamondoid nanofactories that can build nanorobots. Achieving this new technology will require the significant further development of four closely related technical capabilities: (1) diamond mechanosynthesis1 (2) programmable positional assembly1 (3) massively parallel positional assembly1 and (4) nanomechanical design. The Nanofactory Collaboration is coordinating a combined experimental and theoretical effort involving direct collaboration among dozens of researchers at multiple institutions in four countries to explore the feasibility of positionally controlled mechanosynthesis of diamondoid structures using simple molecular feedstocks, which is the first step along a direct pathway to developing working nanofactories that can fabricate diamondoid medical nanorobots.