Dynamic modulation of external conditions can transform chemistry into logic gates

We introduce a new method for transforming chemical systems into desired logical operators (e.g. NAND-gates) or similar signal-manipulation components. The method is based upon open-loop dynamic regulation, where external conditions such as feed-rate, lighting conditions, etc. are modulated according to a prescribed temporal sequence that is independent of the input to the network. The method is first introduced using a simple didactic model. We then show its application in transforming a well-stirred cubic autocatalytic reaction (often referred to as the Selkov-Gray-Scott model) into a logical NAND-gate. We also comment on the applicability of the method to biological and other systems.