Some alternative reproductive strategies in artificial molecular machines.

A class of artificial molecular machines consisting of folded and interconnected chains of basic artificial molecule constituents is described. Such machines are shown capable of carrying out any effective computational procedure. They can also produce molecule strings which are coded descriptions of themselves. It is then shown how such machines might reproduce themselves by (1) templating from a coded description, (2) employing their descriptions as blueprints for the active construction of copies of themselves, or by (3) employing partial or complete copies of themselves as blueprints. To obtain these results, the strategy is the following. First it is shown how the tape accessing, tape movement, instruction types, and transfer operation of a Wang Universal Turing Machine can be achieved in the molecular machine format. Then a way of implementing, in a molecular machine, the result by C. Y. Lee that Wang Turing machines can describe themselves, is demonstrated. The self-describing tactic is then successively elaborated, the molecular machine capabilities augmented, and the molecule-machine structure re-designed to obtain the results noted.