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An air-breathing micro direct methanol fuel cell (μDMFC) with a compound anode flow field structure (composed of the parallel flow field and the perforated flow field) is designed, fabricated and tested. To better analyze the effect of the compound anode flow field on the mass transfer of methanol, the compound flow field with different open ratios (ratio of exposure area to total area) and thicknesses of current collectors is modeled and simulated. Micro process technologies are employed to fabricate the end plates and current collectors. The performances of the μDMFC with a compound anode flow field are measured under various operating parameters. Both the modeled and the experimental results show that, comparing the conventional parallel flow field, the compound one can enhance the mass transfer resistance of methanol from the flow field to the anode diffusion layer. The results also indicate that the μDMFC with an anode open ratio of 40% and a thickness of 300 µm has the optimal performance under the 7 M methanol which is three to four times higher than conventional flow fields. Finally, a 2 h stability test of the μDMFC is performed with a methanol concentration of 7 M and a flow velocity of 0.1 ml min−1. The results indicate that the μDMFC can work steadily with high methanol concentration.

A micro direct methanol fuel cell (μDMFC) is suitable for use in notebook computers, mobile phones, and other digital products. To resolve the poor mass-transport efficiency problem in the anode flow channel, this paper presents an N-inputs-N-outputs parallel flow pattern with rectangular convexes to reinforce methanol mass transport and reduce concentration polarization. The simulation results show that the N-inputs-N-outputs parallel flow channels with the rectangle convexes improve the performance. μDMFCs, which have four anode flow patterns, are fabricated using MEMS (microelectromechanical systems) technology. The experimental results show that the μDMFC with the rectangle convexes has a performance better than previously reported systems, and has a peak power density of 19.96 mW/cm 2 . The simulation and experimental results are in good agreement.

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