Open Access Water Management in Micro Direct Methanol Fuel Cells: Using Inte- grated Passive Micromixer Chun-You Lin*

Abstract: In a DMFC (direct methanol fuel cell), water management is a critical issue for enhancing DMFC power per-formance and lifetime. However, the methanol-water mixing tank for water management is difficult to be miniaturized and integrated into a micro-DMFC. This paper proposes an in-fuel cell micromixer, the self-vortical micromixer, which belongs to a passive micromixer, to perform methanol and water mixing inside a micro-DMFC. Experimental results demonstrate the design, fabrication, and testing results of the self-vortical micromixer integrated with the micro-DMFC, showing that the self-vortical micromixer has high fluidic mixing performance and can be oper-ated in the micro-DMFC as a methanol-water mixing tank for water management of the micro-DMFC. The power performance testing results demonstrate that the single cell of micro-DMFC, with the included self-vortical micromixer, exhibits a maximum power density of 21.27 mW/cm