Part 2 of a series on the history and prospects of advanced nanotechnology concepts,
prompted by the upcoming 50th anniversary of Feynman’s historic talk,
“There’s Plenty of Room at the Bottom”.
As cognitive psychologists know, we human beings suffer from multiple, systematic cognitive biases, aberrations of intellectual vision that can be corrected, in part, when we recognize their operation in our own minds. One is a bias toward expecting causes to resemble their effects, the implicit, default assumption that like causes like.
This bias has, I think, impeded full recognition of the most important line of progress toward molecular manufacturing, and has likewise impeded recognition of where that progress can lead. This is a line of progress that I’ve advocated since the beginning, and that I helped to kick-start: engineering complex, self-assembling molecular systems as an indirect approach to implementing systems that will look very different. That difference, of course, is what triggers the cognitive bug.
The cognitive bug
John Stewart Mill described the like-causes-like bias as
…the most deeply-rooted, perhaps, of all which we have enumerated: one which not only reigned supreme in the ancient world, but still possesses almost undisputed dominion over many of the most cultivated minds….This is, that the conditions of a phenomenon must, or at least probably will, resemble the phenomenon itself.
Current progress (obscured by that cognitive bug)
This bias tends to distort perceptions of progress in molecular manufacturing because, at this stage of development, steps toward high-throughput atomically precise manufacturing (HT-APM) do not look like HT-APM. Filtering one’s comprehension through the representativeness heuristic can make such progress virtually invisible, no matter how large it may be.
The progress I have in mind centers on advances in atomically precise fabrication by chemical and biological means, and these advances now have reached a level that places the implementation of first-generation artificial APM systems within reach. These, however, also won’t resemble slick, large-scale, general-purpose HT-APM systems. Instead, they will support the implementation of more-capable second-generation APM systems that can support a fast design-build-test cycle and thereby enable a well-focused and well-organized develpment program to rapidly ascend a ladder of technologies leading to HT-APM.
Available technologies now enable the design and fabrication of intricate, atomically precise nanometer-scale objects made from a versatile engineering polymer, together with intricate, atomically precise, 100-nanometer scale frameworks that can be used to organize these objects to form larger 3D structures. These components can and have been designed to undergo spontaneous, atomically precise self assembly. Together, they provide an increasingly powerful means for organizing atomically precise structures of million-atom size, with the potential of incorporating an even wider range of functional components.
Lines of advance (obscured by the same bug)
Unfortunately, the representativeness heuristic strongly opposes recognition and exploitation of the power of this emerging technology base.
The nanometer-scale objects that I mentioned above have nylon-like backbones that link and organize an extraordinarily diverse set of molecular components to form structural elements, electronic devices, and machines. The problem is that because they are traditionally called “protein molecules” their nature is obscured by a powerful association with food. The frameworks have a similar representativeness-heuristic problem: “DNA” makes one think of genetic information in cells, but structural DNA nanotechnology uses it as a construction material.
We now have in hand the engineering materials for a new, breakthrough class of nanosystems, yet the bug in our minds whispers “meat” and “genes”. And even in more sophisticated minds, the biological origin of the these materials encourages the seductive idea that their engineering is a task that can be left to biologists. Developing complex, functional systems, however, is quite unlike studying complex, functional systems that already exist. In science, nature provides the pattern. In engineering, human beings provide the pattern. The difference in tasks and mindsets is profound.
In my view, these problems of perception and organization are the chief obstacles to more rapid progress in developing molecular machine technologies on the critical path to fulfilling the promise that launched the field of nanotechnology.
Recent landmarks in atomically precise self-assembly:
Directions in atomically precise fabrication:
- Part 1 — The promise that launched the field of nanotechnology
- Part 2 — Molecular Manufacturing: Where’s the progress?
- Part 3 — The Molecular Machine Path to Molecular Manufacturing (1)
- Part 4 — The Molecular Machine Path to Molecular Manufacturing (2)
- Part 5 — “There’s Plenty of Room at the Bottom” (29 December 1959)
Studies of advanced atomically precise fabrication:
- Roadmap for Atomically Precise Nanofabrication and Productive Nanosystems
- U.S. National Academies report on molecular manufacturing
- Nanosystems: Molecular Machinery, Manufacturing, and Computation,
and its precursor, my MIT dissertation:
“Molecular Machinery and Manufacturing with Applications to Computation” [pdf, 30 MB]