Materials Chemistry, Short talk
Mat-014

Toward Chemical Processors: Programmable Reaction-Diffusion Networks in Silicon Microreactors

S. Agostini1,2, V. Zarth1, M. Fasching1, P. Schwaller2,3, J. Pérez-Mercader4, A. W. Knoll1*, H. Wolf1*
1IBM Research Europe – Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland, 2Laboratory of Chemical Artificial Intelligence, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland, 3National Centre of Competence in Research (NCCR) Catalysis, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland, 4Department of Earth and Planetary Sciences, Harvard Origins of Life Initiative, Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA

Chemical systems capable of autonomous spatiotemporal dynamics offer an energy efficient physical substrate for information processing beyond conventional electronic materials. Here, we present a microfabricated silicon platform that confines the oscillatory Belousov–Zhabotinsky reaction in networks of coupled microreactors, forming an excitable reaction–diffusion medium for chemical signal processing.
Within the silicon microreactor platform, micrometer-scale reactors connected by nanochannels support propagating chemical excitation waves that serve as signals. We experimentally demonstrate wave transmission between coupled reactors, geometry-defined propagation pathways, delayed signal arrival, signal regeneration, and fan-out in branching network structures. These functions arise from the nonlinear autocatalytic dynamics of the Belousov–Zhabotinsky reaction, which provide intrinsic thresholding and amplification, while the microfabricated network geometry defines connectivity and coupling strength.
Using the same silicon microreactor platform, we realize a chemical XOR operation based on coincident excitation, demonstrating nonlinear signal integration in a spatially extended chemical medium. This result shows that engineered reaction–diffusion networks can implement elementary logic-like functionality through collective chemical dynamics.

To explore a route toward dynamic programmability, we perform complementary macroscopic experiments showing that electrochemical biasing can modulate Belousov–Zhabotinsky oscillations through locally generated activator molecules that are amplified by the reaction network [1]. This electrochemical control is not yet integrated into the silicon microreactor platform, but it motivates future architectures in which fixed microreactor geometry defines the computational graph and patterned electrodes provide addressable, programmable control.
Together, these results establish silicon-based chemical microreactor networks as active materials for reaction–diffusion signal processing. They represent a step toward chemically active processor architectures capable of nonlinear signal propagation, integration, and adaptive response, with potential applications in sensing, autonomous operation, and unconventional information processing.

[1] S. Agostini, P. Schwaller, J. Pérez-Mercader, A. Knoll, H. Wolf. From Microcurrents to Macrodynamics: Harnessing Mixed Potentials for Large, Tunable Acceleration of Belousov–Zhabotinsky Oscillations. ChemRxiv. 05 March 2026. DOI: https://doi.org/10.26434/chemrxiv-2025-wrt8d/v4