Dynamics and Control of Integrated Microchemical Systems*

Microchemical systems are a new generation of miniature chemical systems that carry out chemical reactions and separations in precisely fabricated three dimensional microreactor configurations in the size range of a few microns to a few hundred microns. Typical microchemical systems combine fluid handling and reaction capabilities with electronic sensing and actuation, are fabricated using integrated circuit (IC) manufacturing techniques and use silicon and related IC industry materials, polymers, ceramics, glass or quartz as their material of construction. The use of such systems for in-situ and on-demand chemical production is gaining increasing importance as the field of microreaction engineering transitions from a theoretical concept to a technology with significant industrial applications. In this paper, we provide an overview of the issues involved in modeling, design and control of microchemical systems and as examples, demonstrate some of these concepts with our work on modeling and control of microreformers for hydrogen delivery systems in micro-fuel cells. The paper concludes by suggesting possible areas of future research.