Engines of Extinction: Episode I - The End & The Means by Martin Chris

Author:Martin, Chris [Martin, Chris]
Language: eng
Format: mobi
Tags: Military Science Fiction
Published: 2015-03-10T07:00:00+00:00

Molecular manufacturing (MM) is based around the idea of mechanosynthesis -- the ordered and directed reaction of one molecule with another by mechanical constraints (accomplished by a molecular fabricator). This is opposed to conventional chemosynthesis, in which millions of reactive molecules collide and bond in a liquid or vapor via random thermal motion.

Molecular manufacturing is defined as the “programmed chemical synthesis of complex structures by mechanically positioning reactive molecules.” Effectively, MM is mechanosynthesis -- physically moving single atoms into a desired position -- performed in a structured, massively parallel manner by utilizing countless molecular fabricators working together in concert. This would enable the fabrication of nano- and macro-scale products that are atomically exact, allowing for a paradigm-shifting degree of engineering precision and complexity.

In 2003, a rudimentary form of mechanosynthesis was first achieved with silicon via a scanning tunnel microscope, providing evidence that full-scale MM might someday be feasible. A primitive synthetic ribosome analog -- a hardwired polymer/protein-based molecular assembler -- has just been developed by a team in the School of Chemistry at the University of Manchester, demonstrating genuine progress toward that end goal.

Forms of atomically precise manufacturing (APM) already exist, although they remain extremely limited -- both in volume and in capability -- especially when compared to MM (sometimes referred to as high-throughput atomically precise manufacturing [HT-APM]).

An oft-cited, idealized end goal (perhaps better thought of as a new starting point) for researchers actively investigating the plausibility of molecular manufacturing is the development of diamondoid mechanosynthesis (DMS) and, ultimately, diamondoid molecular manufacturing. DMS is the basic process of mechanosynthesis applied to covalently bonded carbon (diamond) and other stiff covalent solids with similar properties to build diamondoid structures. This takes advantage of their immensely strong bonds to fabricate products with previously unheard-of qualities.

Incremental advancements of today’s methodologies appear to point the way to generalized molecular manufacturing. Reviewing the topic touched upon in the previous section, today’s practices generally fall into two general camps:

Tip-based AMP involves manipulating the topography of a surface with atomic precision via scanning probe microscopy, removing or depositing single atoms in preprogrammed patterns. This is possible across a wide range of materials and molecules; however, the process is slow and has generally been limited to displacing weak bonds at a surface level.

Bio-based APM involves using DNA origami or engineered synthetic proteins (called foldamers) to build atomically precise structures. Increasingly complex three-dimensional shapes are being constructed via these methods. However, these biopolymers have a limited range of properties and rigidity. The complexity allowed by these programmed structural frameworks is quite limited, as the field is still in its relative infancy.

The strengths and weaknesses of these contrasting methods are complementary. As such, the bio- and tip-based methods have begun to converge as demonstrated by the Chinese Modular In-vivo Nanosystem Generation program. In this case, bio-based methods of directed self-assembly are used to position functional components (including high-performance tip-based APM products) in an atomically precise manner. Complex products of this type, such as those found in the interrelated MING ecosystem, can be categorized as modular molecular composite nanosystems.

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