Microchemical systems for discovery and development

Applications of silicon-based microreactors are summarized starting with systems for single-phase organic transformations and progressing through multiphase catalytic systems to microsystems for multistep chemical synthesis. The latter systems involve extraction and gas-liquid separation processes designed to take advantage of the dominance of surface tension effects in microfluidic devices. Integration of physical sensors (e.g., for pressure, temperature, and flow) and measurements of chemical species further enhances the utility of microreactors by enabling chemical kinetic studies and optimization of optimal operating conditions. A brief description of synthesis and handling of solid particulates is included, with particular emphasis on multistep processing of colloidal nanoparticles. Finally, scale-up issues and challenges to the adoption of microreaction technology are discussed.