Programmable spatiotemporal chemical computers powered by temperature gradient

Life on Earth sustains its functions by capturing energy from the environment, mainly through light or chemical compounds. Recent work has shown that heat cycling can also be used to power molecular computation in rationally designed chemical systems. Akin to how a chemical gradient between inside and outside of cells can autonomously sustain out-of-equilibrium behavior, here we investigate whether a steady-state temperature gradient could, in principle, sustain computation and spatiotemporal pattern formations for arbitrarily long periods of time. We show that enclosed chemical systems diffusing within a temperature gradient can be powered analogously to a continuous stirred-tank reactor (CSTR)—a well-mixed reactor with a constant inflow of target molecules and outflow of all components— upon proper design of temperature-dependent free energies of molecules. This connection between CSTR dynamics and chemical systems powered by temperature gradients opens pathways for designing programmable spatiotemporal modules. To demonstrate this, we develop oscillators, binary pulse counters, and spot- and stripe-forming systems, suggesting a general strategy for designing chemical systems that harness environmental energy to process information.