The Rebel Faction

Assembler and Disassembler (Two R&D's)

An assembler is a molecular construction device. It will have one or more submicroscopic robotic arms under computer control. The arms will be capable of holding and positioning reactive compounds so as to control the precise location at which a chemical reaction takes place. The assembler arms will grab a molecule and add it to the workpiece, constructing an atomically precise object step by step. An advanced assembler will be able to make almost any chemically stable structure. In particular, it will be able to make a copy of itself. Since assemblers can replicate themselves, it is easy to produce them in large quantities.

Nature features a biological parallel to the assembler: the ribosome. Ribosomes are in our cells which manufacture all the proteins used in all living things on Earth. They do this by assembling amino acids, one by one, into precisely determined sequences. These then fold up to form a protein. The blueprint that specifies the order of amino acids, and thus indirectly the final shape of the protein, is called messenger RNA; and the messenger RNA is in turned determined by our DNA, which can be viewed as an instruction tape for protein synthesis.

To build something, all you will need is a detailed design of the object you want to make and a sequence of instructions for its construction. Rare or expensive raw materials are generally unnecessary; the atoms required for the construction of most kinds of devices exist in abundance in nature. Dirt, for example, is replete with useful atoms.

By working in large teams, assemblers and more specialized nanomachines will be able to build large objects quickly. Consequently, while assemblers may have features on the scale of a nanometer or less the products could be as big as blasters or even the size of ships engines.

Because assemblers will be able to copy themselves, products will have low marginal production costs – perhaps on the same order as such commodities from nature (firewood, hay, or potatoes). By ensuring that each atom is properly placed, they will manufacture products of high quality and reliability. Leftover molecules would be subject to this strict control, making the manufacturing process extremely clean.

The speed with which designs and instruction lists for making useful objects can be developed will determine the speed of progress after the creation of the first full-blown assembler. Powerful software for molecular modeling and design will accelerate development, possibly assisted by specialized engineering AI. Another accessory that might be especially useful is the disassembler, a device that can disassemble an object while creating a 3D map of its molecular configuration. Working in concert with an assembler, it could function as a kind of 3D Xerox machine, which could make atomically exact replicas of almost any existing solid object within reach.

These assemblers can process almost a million molecules per second, even without conveyors and power-driven mechanisms to slap a new molecule into place as soon as an old one is released. It might seem too much to expect an assembler to grab a molecule, move it, and jam it into place in a mere millionth of a second. But small appendages can move to and fro very swiftly. A human arm can flap up and down several times per second, fingers can tap more rapidly, a fly can wave its wings fast enough to buzz, and a mosquito makes a maddening whine because an insect's wing is about a thousand times shorter.

An assembler arm will be a great deal shorter than a human arm, and so it will be able to move back and forth about a great deal more rapidly. For an assembler arm to move a mere million times per second would be like a human arm moving about once per minute: sluggish. So it seems a very reasonable goal.