Achieving Operational Universality through a Turing Complete Chemputer

The most fundamental
abstraction underlying all modern computers
is the Turing Machine, that is, if any modern computer can simulate
a Turing Machine, an equivalence which is called “Turing completeness”,
it is theoretically possible to achieve any task that can be algorithmically
described by executing a series of discrete unit operations. In chemistry,
the ability to program chemical processes and ensure unit operations
are understood at a high level of abstraction and then reduced to
practice is extremely challenging. Herein, we exploit the concept
of Turing completeness applied to robotic chemical platforms that
execute unit operations to synthesize complex molecules using a chemically
aware programming language, XDL. We leverage the concept of computability
by computers to synthesizability of chemical compounds by automated
synthesis machines. The results of an interactive demonstration of
Turing completeness using the color gamut and conditional logic are
presented to serve as a proxy for conceptual, chemical space exploration.
This formal description establishes a formal framework in future chemical
programming languages to ensure complex logic operations are expressed
and executed correctly, with the possibility of error correction,
in the autonomous pursuit of increasingly complex molecules.