Time-dependent measurements for the mapping Of Current distribution via a segmented flow field plate approach in a micro-proton exchange membrane (PEM) fuel cell were conducted and the effects of flow field configuration were Studied and discussed Under fixed operating conditions. The results show that, among four flow fields studied herein, the interdigitated flow channel has the most uniform transient current distribution with a much higher water content at an early phase (say t < 0.5 h) than those of the other three channels: serpentine, mesh and parallel, indicating an adequate oxygen concentration of the airflow on the cathode. In addition, the effect of water content on current distribution was also examined and discussed. It was found that the Volume of water in flow channels could reach a steady value of 45% for all four flow fields after a 3-h operation. (C) 2008 Elsevier B.V. All rights reserved.