Fuel and CO2 self-exchange system with micro fluid channels for a micro direct methanol fuel cell

This paper shows a self-exchange system to supply liquid fuel and to exhaust CO₂ spontaneously for micro direct methanol fuel cell (muDMFC). The system performs effectively and continuously without any circulation loops and external pumps. The fuel is carried to the anode due to capillary force. The system is consisted of a hydrophobic porous membrane and two comb-shape channels. It was confirmed that the muDMFC works with a less differential pressure than1 kPa between a fuel inlet and a CO₂ outlet. The fuel supply rate of only several mul/min/cm² was needed for the DMFC to work. Furthermore, the fuel supply rate was spontaneously varied along the electric current with constant pressure.