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 present a review of our work on MEMS-based microfabrication, modeling and control of micro-reformers for hydrogen delivery systems in micro-fuel cells and put it in the context of a number of reported studies in the literature on this topic. The paper concludes by suggesting possible areas of future research. (c) 2006 Elsevier Ltd. All rights reserved.