Fuel flow rate, temperature and pressure significantly influence the working efficiency of micro-reformers. Owing to their large volumes, conventional sensors can only be used to evaluate the outfield of a reformer and the inlet or outlet of a fuel gas cylinder. However, such measurements may not accurately reflect working conditions inside a micro-reformer. Therefore, in this study, micro-sensors are fabricated in a micro-reformer for monitoring temperature and flow distributions in situ by using micro-electro-mechanical systems (MEMS) technology. Additionally, the performance of a micro-reformer is compared with that of various micro-channel types. Results of this study provide a valuable reference for efforts to commercialize micro-reformers in the future. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.