The effect of the anode flow field design on the performance of an in-house fabricated micro direct methanol fuel cell (mu DMFC) with an active area 1.0 cm x 1.0 cm was investigated experimentally. Single serpentine and parallel flow fields consisting of micro channels were tested. The experimental results indicated that the serpentine flow field exhibited significantly higher cell voltages than did the parallel flow field, particularly at high current densities. The study of the effect of channel depth of the serpentine flow field suggested that there exists an optimal channel depth for the same channel width and the same open ratio when the same methanol flow rate is supplied; either shallower or deeper channels will lead to a reduction in the cell performance. Finally, it was demonstrated that performance of the mu DMFC with the reactants fed by an active means was insensitive to the cell orientations, which is different from conventional DMFCs with larger flow channels reported in the literature. (c) 2005 Elsevier B.V. All rights reserved.