Embedded self-circulation of liquid fuel for a micro direct methanol fuel cell

This paper introduces a micro direct methanol fuel cell (muDMFC) with an embedded self-pumping mechanism to deliver liquid fuel. The fuel is propelled by the CO₂ bubbles generated by the fuel-cell electrochemical reaction, and the bubbles are removed from the system during the self-pumping process. Furthermore, the pumping rate is self- regulated by the reaction, i.e., by the electric load. By eliminating the need for a pump and gas/liquid separator, our design allows much simpler fuel-cell systems, which is especially beneficial for miniaturization. Although we test with muDMFC in this paper, the mechanism applies to other membrane electrode assembly (MEA)-based fuel cells with organic liquid fuels as well.