In Situ Visual Investigation of CO2 Bubbles Clogging Phenomena in μDMFC Anode Micro Flow Field

The CO₂ bubbles clogging in anode flow field is a vital problem in development of liquid feed micro direct methanol fuel cells (μDMFC). In order to study the CO₂ bubbles clogging behavior, an air-breathing transparent μDMFC with 180 μm wide serpentine channels in anode was fabricated. In situ visual investigation of the bubbles behavior in anode flow field was implemented on the microfluidics test station. The μDMFC was evaluated under different operating conditions by changing the fuel temperature, concentration and feeding rate. Gradient distribution of the bubbles in micro flow field had been observed, measured and quantitatively analyzed. Results show that the clogging behavior of the bubbles is mainly affected by the current density and feeding rate of the fuel in μDMFC. Meanwhile, the influences of fuel concentration and fuel temperature on bubbles clogging mainly take effect via their impacts on the μDMFC current density