On the response of simple reactors to regular trains of pulses

Propagating pulses of concentration in an excitable system may carry information because regions of high concentration of a selected reagent may be associated with one logical state, and regions of low concentration with another. Spatially distributed reactors constructed of active (excitable) and passive areas in which reagents diffuse can be applied to transform such information. In this paper we consider a few examples of such reactors (a chemical diode, a cross junction switch) and study their response to a chemical input of high frequency. We demonstrate that the response of a signal processing device may depend on the input frequency.