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Rapid development of portable electronic devices and micro/nano systems require micro power sources with high performance.Micro direct methanol fuel cell (μ-DMFC) is a promising technology due to its high energy density,few safety concerns,and capability of quickly starting up.MEMS technology has been utilized for design and fabrication of μ-DMFC where silicon is generally for flow field plate in μ-DMFC.However,due to package requirements a large pressure is put on silicon plates that could easily lead to crack of the cell and leakage of methanol,lowering output performance of μ-DMFC.On the other hand,practical devices and systems generally require high power consumption but output power of a single cell μ-DMFC is small.In this paper,we present a stack μ-DMFC to solve the package challenges of μ-DMFC and raise the power output as well.In our proposed stack μ-DMFC shown in Fig.1,silicon is used as anodic flow field plate but PDMS(Polydimethylsiloxane) used as cathode flow field plate.With this structure,methanol can flows in both pieces of MEA (membrane electrode assembly) of μ-DMFC at the same time to enhance the current density in μ-DMFC.Fig.2 shows 3 types of structure designs for flow channel in the silicon anodic plate,and numerical analyses of fluidic fields in channel are carried out by using the FLUENT software,as shown in Fig.3.Fig.4 shows the microfabricated anodic flow field plate using silicon,and Fig.5 shows the microfabricated cathode plate using PDMS,in which its conducting performance is improved by integrating copper foil into the cathode flow field plate.A packaged stack μ-DMFC is shown in Fig.6 and its tested output performance is shown in Fig.7.The results show that crack and methanol leakage can be effectively avoided in the developed μ-DMFC and its output performance are greatly improved,with output voltage of 0.5V,current density of 81.25mA/cm2 and power density of 7.73mW/cm2.