Abstract
A novel design of multi-sectional flow field for cathode side of small or micro DMFC is fabricated using MEMS and precision machining processes. The flow field includes a parallel-channel section, buffer zone and recycling channels. The preliminary tests of water wetting process in the flow field show that the flow field with hydrophilic surface can provide a favorable recycling ability. The in-situ observation of actual single DMFC shows the different behaviors of water respectively associated with stainless steel mesh and carbon cloth. Furthermore, the in-situ observation indicates the water transport behavior in the parallel channels. All the channels with observation opening are found to be free from water clogging even at a low air flow rate (< 10 ml/min). This novel flow filed is experimentally demonstrated to handle the water generation and prevent water clogging in the channels. In the test of single DMFC, flow field with gold-plated surface and deeper channel depth can obtain maximum current and power output for about 4.6 and 5.6 times compared with flow field with SiO2-induced surface.