Robert A. Freitas Jr. has written pioneering books on nanomedicine,
nanorobots, and molecular manufacturing. What’s next? The last two books in the Nanomedicine series and a book on fundamentals of nanomechanical engineering, extending Eric Drexler’s classic Nanosystems, he reveals in this interview.

Originally published on Nanotech.biz November 4, 2005. Reprinted on KurzweilAI.net February 2, 2006.

Robert A. Freitas Jr., J.D., published the first detailed technical design study of a mechanical nanorobot ever published in a peer-reviewed mainstream biomedical journal and is the author of nanomedicine, the first book-length technical discussion of the medical applications of nanotechnology and medical nanorobotics.

Question 1: Tell us about yourself. What is your background, and what is your current affiliation?

I received an undergraduate B.S. degree from Harvey Mudd College (dual major, physics and psychology) in 1974 and a Juris Doctor (J.D.) graduate degree from University of Santa Clara School of Law in 1978. In the late 1970s and early 1980s I published numerous editions of Lobbying for Space, the first space program political advocacy handbook ever published, and conducted three separate observational SETA/SETI programs with a colleague, using both optical and radio telescopes. I 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. After a stint as Research Scientist at Zyvex Corp. from 2000-2004, I’m now back with the Institute for Molecular Manufacturing, my previous and current primary affiliation, as their Senior Research Fellow.

Question 2: When and how did you first hear about molecular nanotechnology? At what point did you decide to devote your career to this field?

The first time I ever thought about atomic-scale engineered objects was probably in 1977-78, when I was working on my first treatise-length book project (Xenology). In Chapter 16 of that book, I hypothesized that “using molecular electronics with components on the order of 10 Å in size, 10¹⁰ microneurons could be packed into a space of a few microns” which would be “small enough to hide inside a bacterium.” During my NASA work on self-replicating machines in the summer of 1980, I wondered how small machine replicators might be made. I briefly studied the emerging micromachine technology, but by the time Engines of Creation came out in 1986 I had temporarily left the field in pursuit of more pragmatic opportunities. In early 1994 I happened to pick up and read a copy of Unbounding the Future. This was my first exposure to what has come to be known as molecular nanotechnology (MNT). I studied the detailed technical arguments presented in Nanosystems, which confirmed what I had already suspected based on my own knowledge—namely, that the technical case for molecular nanotechnology was very solid.

Having fully absorbed the MNT paradigm, I immediately realized that medicine would be the single most important application area of this new technology. In particular, nanomedicine offered a chance for significant healthspan (healthy lifespan) extension. It also appeared that this objective could possibly be achieved within the several decades of life actuarially remaining to me and others of my generation. But was anyone pushing it forward? I contacted the Foresight Institute and learned that nobody had yet written any systematic treatment of this area, nor was anyone planning to do so in the near future. So I took up the challenge of writing Nanomedicine, the first book-length technical discussion of the potential medical applications of molecular nanotechnology and medical nanorobotics.

I’ve been writing the Nanomedicine book series since 1994.  This technical book is my attempt to rationally assess various possible nanorobotic capabilities and medical systems to determine which ones might be plausible (and which ones not) if we could build nanorobots at some point in the future. The first volume (I) was published by Landes Bioscience in 1999 and is freely available online at http://www.nanomedicine.com/NMI.htm.  The second volume (IIA) was also published by Landes Bioscience, in 2003, and is also freely available online at http://www.nanomedicine.com/NMIIA.htm.  I’m still writing the last 2 volumes (IIB, III) of this book series, an ongoing effort that will continue during 2005-2010.

Question 3: Recently, the Foresight community has de-emphasized molecular assemblers in favor of a desktop manufacturing paradigm. What brought about this shift? How will this change affect the field?

While I’m not involved in the decisions of the Foresight Institute, I believe the shift occurred primarily as an attempt to redirect the often rancorous scientific debate away from the growing fears of runaway motile free-range replicators, and away from the seeming impossibility of building self-replicating machines (a prejudice common to many ill-informed scientists), and towards a more rational consideration of the underlying technologies and their benefits. The civility of the public discourse may improve as a result, and to the extent that the mainstream scientific community begins to pay attention, it is possible that the research funding situation might also improve. I’m all for it.

However, the change probably won’t much affect the actual research in the field, nor the achievement of useful results per dollar spent, because in truth the distinction between “molecular assemblers” and “nanofactories” is largely cosmetic. That is, if you possess either one, you can use it either to replicate itself or to build the other in very short order. Either one can be used equally well to build life-saving medical nanorobots or life-denying nanoweapons, including everyone’s favorite bugaboo, the marauding ecophages. Both assemblers and nanofactories are examples of molecular manufacturing, which depends at its core on some form of replicative or massively-parallel fabrication and assembly capability in order to be able to economically generate macroscale quantities of useful end products. The two approaches differ mainly in their technical design/performance tradeoffs. Each approach has different strengths and weaknesses (as manufacturing systems) that can be readily enumerated. I’ve been writing about both approaches since the 1980 NASA replicating factory study – wherein I was actually the main proponent for the factory approach. The key thing is that molecular assemblers and nanofactories are both molecular manufacturing systems. Each requires almost exactly the same set of enabling technologies. Developing those enabling technologies as soon as possible should be our primary focus right now.

Question 4: Do you agree with those who claim that the desktop manufacturing paradigm could become a reality by 2020?

I would not be surprised if the fabrication of medical nanorobots (and other useful nanorobotic systems) via molecular manufacturing – whether via molecular assemblers or nanofactories – arrives during the decade of the 2020s.

As noted earlier, I undertook the Nanomedicine book series in an attempt to establish a solid foundation for the single most important future application of MNT. The book introduces a long-term vision for nanorobotic medicine and articulates the technical underpinnings of that vision, so that when the day arrives that we have the technology to build such devices, we’ll have a clearer idea what can be done with them, and how.

More recently, to answer those who remain skeptical of the entire MNT enterprise, including the possibility of medical nanorobotics, I’ve turned my attention to figuring out how to build the nanorobots – the issue of implementation of the long-term vision.  My early work on diamond mechanosynthesis is described in a lecture I gave at the 2004 Foresight Conference in Washington DC, the text of which (plus many images) is available online.  I’m now involved in 6 research collaborations with various university and corporate groups in the U.S, U.K. and Russia in an effort to push forward the technology in this area as fast as possible. These collaborations include a variety of computational chemistry simulations of plausible mechanosynthetic tooltips and reaction sequences, coupled with a nascent experimental effort that is just starting up. I have several new papers on diamond mechanosynthesis nearing completion for journal submission, for publication in 2006. Earlier this year I also filed the first-ever U.S. patent on diamond mechanosynthesis that describes a specific process for achieving molecularly precise diamond structures in a practical way.

Ralph Merkle and I are also writing an entire book-length discussion of diamond mechanosynthesis, entitled Diamond Surfaces and Diamond Mechanosynthesis (DSDM), to be published in 2006 or 2007. The first half of this book is an extensive review of all that is presently known about diamond surfaces, and has been mostly written for several years. The second half describes specific tools and reaction pathways for building those surfaces using positionally controlled mechanosynthetic tools, and methods for building those tools. This part has been about 50% written for several years. But finishing this part has been put on hold because our many current research collaborations involving ab initio and DFT-based quantum chemistry simulations are providing so much new information that we think it’s better to wait and incorporate this new material into the book. (Otherwise we could’ve published DSDM in 2005.) Until then, I’ve put together a brief technical bibliography of research on positional mechanosynthesis (including diamond). Watch the Molecular Assembler website for updates and further news about DSDM.

Question 5: Tell us about your latest book, Kinematic Self-Replicating Machines. Was this book written with the specific aim of convincing skeptics of the feasibility of molecular manufacturing?

Yes it was, though of course the subject of self-replicating machines has been a long-standing professional interest of mine, across 3 decades. For instance, I published the first quantitative closure analysis for a self-replicating machine system in 1979-1980 and participated in (and edited) the first comprehensive technical analysis of a self-replicating lunar factory for NASA in 1980.

But focusing again on molecular manufacturing: Once diamond mechanosynthesis and the fabrication of nanoparts becomes feasible, we will also need a massively parallel molecular manufacturing capability in order to assemble nanorobots cheaply, precisely, and in vast quantities.  Kinematic Self-Replicating Machines (KSRM) (Landes Bioscience, 2004, and freely available online), co-authored with Ralph Merkle, surveys all known current work in the field of self-replication and replicative manufacturing, including all known concepts of molecular assemblers and nanofactories. It is intended as a general introduction to the systems-level analysis of self-replicative manufacturing machinery. With 200+ illustrations and 3200+ literature references, KSRM describes all proposed and experimentally realized self-replicating systems that were publicly disclosed as of 2004, ranging from nanoscale to macroscale systems.  The book extensively describes the historical development of the field.  It presents for the first time a detailed 137-dimensional map of the entire kinematic replicator design space to assist future engineering efforts.  It includes a primer on the mathematics of self-replication, and has an extensive discussion of safety issues and implementation issues related to molecular assemblers and nanofactories. KSRM has been cited in two articles appearing in Nature this year (Zykov et al, Nature 435, 163 (12 May 2005) and Griffith et al, Nature 437, 636 (29 September 2005)) and appears well on its way to becoming the classic reference in this field.

Perhaps the most salutary effect of KSRM is that it provides a number of physical examples of self-replicating systems (beyond the relatively simple autocatalytic-type replicators from the 1950s by Penrose, Jacobson and Morowitz and the more recent related examples by Lohn and Griffith) that have already been built and operated in a laboratory environment. This provides a ready answer to the tedious and recurring objection by the ill-informed that such things are “impossible”: The machines have actually been built. Interestingly, one of these experimental replicators is a fully autonomous machine that runs around on a table and procures its own parts, which it then assembles into a working copy of itself, a crude analog of the molecular assembler approach. Another of these experimental replicators is a computer-controlled manipulator arm anchored to a surface, that grabs its parts from a “warehouse” area and assembles these parts into a working copy of itself, a crude analog of the nanofactory approach (where the nanofactories are being used to make more nanofactories, rather than nonfactory product).

Question 6: You and Dr. Hall are working on Fundamentals of Nanomechanical Engineering. Is this book intended to serve as a guide book for college students hoping to enter the nanotechnology field?

Fundamentals will be sharply focused on nanomechanical design, with a concentration on diamondoid molecular machine systems, intended for use in a mechanical engineering curriculum at the 2nd- or 3rd-year undergraduate level. We hope the book will be widely used in nanotechnology courses and will help to train the first generation of nanomechanical design engineers.

This is the primary purpose of the book. A second purpose is to extend and complement the analyses already published in Drexler’s Nanosystems, providing more design details and engineering analysis of how to build structures with molecular precision, and understanding how molecular machines might function (and the limitations on them).  Once an experimental ability to build diamondoid gears, bearings, rods, and the like has been demonstrated in the laboratory, I think the development of nanorobotics will move very rapidly from that point, because the potential payoff to human welfare is so large and the design space will have become accessible to active experimentation.

Question 7: MIT granted Eric Drexler a PhD in molecular nanotechnology. How long do you estimate before other Universities offer undergraduate and graduate degrees in molecular nanotechnology?

If you mean college degrees in MNT, in the sense of diamondoid molecular machine systems, I think this will begin to occur as soon as the field gains scientific credibility – i.e., as soon as it becomes clear that there is a “there,” there. The key here, in my opinion, will be the first experimental demonstration of positionally controlled diamond mechanosynthesis in the laboratory. Once this has been done, it will no longer be possible for critics to deny that such a thing is possible, though they still may claim that perhaps such a thing is not very useful for anything important. But with the newfound ability to tinker with real atoms, I expect legions of graduate students to rise up and prove the critics wrong on that score too, and the results of this revolution will rapidly trickle down to the undergraduate level as well.

How long until the first simple experimental demonstration of positionally controlled diamond mechanosynthesis in the laboratory? Perhaps not as far off as you might think. I’d be shocked if it was longer than 10 years, and 5 years would not surprise me. It depends on how fast we’re able to push it forward.

Question 8: You are a scientific advisor to the startup nanotechnology company Nanorex. What role do you anticipate that Nanorex will play in the development of nanotechnology? What is your contribution to that company?

Nanorex is creating an incredibly cool piece of software called NanoEngineer that allows the user to quickly and easily design molecular machine systems of up to perhaps 100,000 atoms in size, then perform various computational simulations on the system such as energy minimization (geometry optimization) or a quantitative analysis of applied forces and torques. It’s a CAD system for molecules, with a special competence in the area of diamondoid structures. Once this software is released, users anywhere in the world will be able to begin creating designs for relatively complex nanomachine components. We’d expect the library of designed machine systems to rapidly expand from the current 1-2 dozen items (including mostly just a few bearings, gears, and joints) into the hundreds or thousands in just a few years. The existence of this expanded library of nanoparts will then make it easier to begin thinking about designs for more complex systems that may be built from thousands or more of these parts, containing millions or even billions of atoms. It’s a big step along the molecular machine design and development pathway.

I’m a member of the Scientific Advisory Board of Nanorex. The Board provides feedback in the development of the NanoEngineer software, especially including our respective “wish lists” of what the ideal molecular machine design package should include – most of which features were then incorporated into the software. Thus the new software reflects the collective experience of those few of us in the world who have ever actually designed a molecular machine component the hard way – laboriously, atom by atom, using some previously existing (inadequate) software package.

Nanorex is also directly supporting the writing of Fundamentals of Nanomechanical Engineering, which we hope will be used to train the first generation of serious nanomechanical design engineers.

Question 9: Is the mainstream scientific establishment’s assessment of the feasibility of molecular nanotechnology changing? It appears that the National Nanotechnology Initiative’s long term forecasts have become bolder, yet the standard response by Smalley and others is that molecular manufacturing is inherently unworkable.

I think this feasibility assessment may be slowly changing, but this change is probably being driven mainly by published experimental results, especially in the field of STM/AFM(scanning probe)-moderated single-atom chemistry. For example, the first experimental demonstration of pure mechanosynthesis of any kind was reported in 2003 and is just now becoming more widely known. Publication of credible high-accuracy theoretical results, demonstrating the feasibility of diamond mechanosynthesis, will also help change this assessment. (For instance, in 2006 Merkle and I will be publishing a key theoretical paper in diamond mechanosynthesis representing ~10,000 CPU-hours of quantum chemistry simulations on 2600+ molecular structures to elucidate possible reaction pathways for building diamond. Watch for it.)

Smalley has marginalized himself in this area by taking such an extreme and indefensible position, using fallacious arguments. One by one, his arguments are slowly melting away under the hot glare of brilliant (but hard-won) experimental results.

Question 10: The Foresight Institute is collaborating with Battelle to create a nanotechnology roadmap. What do you know about this roadmap? Will it affect the mainstream scientific community’s assessment of molecular manufacturing?

Actually, I don’t know anything about their roadmap. They haven’t consulted me at all on this, and I have no idea what they’re up to except what I “read in the newspaper”. I believe it is an attempt to involve mainstream players in an assessment of possible development pathways leading toward some flavor(s) of molecular manufacturing. Whether these flavor(s) will include some or all of biological systems, protein systems, polymer systems, MEMS systems, metal systems, diamondoid systems, or something else, I cannot say.

Meanwhile, over the last two years Ralph Merkle and I have worked hard to establish a small independent network of research (both theoretical and experimental) collaborators with a sharp focus on the implementation of diamondoid molecular machine systems. Last June we put together a simple draft implementation flowchart that has about 100 boxes and lots of arrows, that starts from where we are today and ends with the manufacturing of complex molecular machine systems, including simple nanorobots. The plan includes specific theoretical and experimental milestones in a particular sequence. So we’re in the process of simplifying (and implementing) our own “roadmap”. Perhaps this (or something like it) will eventually be incorporated in the broader Foresight nanotechnology roadmap. Watch the Molecular Assembler website for more details in the months ahead.

Continued in Interview with Robert Freitas: Part 2.

©2006 Sander Olson. Reprinted with permission.