(3dd) Controlling Reaction-Diffusion-Convection for Intelligent and Functional Chemical Systems

Intelligent and functional systems detect cues from its environment, respond appropriately to these cues and perform their intended purposes. At present, development of these systems has relied mainly on electronic-based machineries, devices and robots for solving problems in practically all aspects of our lives. While this approach has largely been successful, the performance of these electronic systems is still far less intelligent than naturally-occurring systems, ranging from a single cell to any larger biological organisms. Despite their complexity, these systems from nature operate almost entirely out of chemical reactions coupled with diffusive and/or convective processes. Learning from these systems and engineering the appropriate reaction and transport processes can provide the solution to non-electronic-based intelligent systems with vast potential.

Examples of such intelligent and functional chemical systems constructed through controlling reaction-diffusion and/or convection include: (1a) Camphor boats which self-assemble and swarm collectively in a biased direction, (1b) oil droplets which solve mazes using the shortest possible route, (1c) programmable reaction-diffusion which allows fabrication of core-shell particles of desired geometries and (1d) core-shell porous materials which perform sequential reactions.

On the other hand, naturally-occurring systems, such as cells, also make use of reaction-diffusion and/or convective processes for intracellular transport and control (*). As such, I am also actively studying cells – in particular, cell mechanics and cell motility. Cells plated on micropatterns, such as (2a) on circular islands of different sizes allow a micromechanical model for different cell types to be constructed (cell shape is defined by cell membrane, cortical actin and supported by its nucleus) and (2b) on lines where movement of migrating non-metastatic, cancerous cells and metastatic, cancerous cells are found to be diffusive and super-diffusive respectively.

Through controlling reaction-diffusion-convection processes in artificial systems and studying natural systems, such as cells, hopefully, more advanced, intelligent and functional chemical systems can be realized.

(*) Soh, S.; Byrska, M.; Kandere-Grzybowska, K.; Grzybowski, B. A. Reaction-Diffusion Systems in Intracellular Molecular Transport and Control. Angew. Chem.-Int. Edit. 2010, 49, 4170-4198.