Hydrophilicity effect on micro-scale flow of μDMFC

• The Lattice-Boltzmann model was established to simulate hydrophilicity effect of μDMFC.
• Bubble dynamics were conducted to investigate bubble behavior at different channels.
• A μDMFC with the active area of 1.0 cm2 was presented to validate the simulation.

The effective removal of carbon dioxide (CO2) in the anode micro channels is critical to the performance of the micro direct methanol fuel cell (μDMFC). A Lattice-Boltzmann model coupled with liquid–gas surface tension, fluid–solid interaction and buoyancy force is adopted in this work to simulate the two-component flow with different hydrophilicity channels. The simulation results show that the emission speed of CO2 gas in the cell patterned with the hydrophilic channel wall is faster than that with the hydrophobic wall. In order to mutually validate the simulation results, a μDMFC with an active area of 1.0 cm2 is designed, fabricated, and tested. Data results show that with improved gas expelling and fuel supplying, the novel μDMFC with the hydrophilic flow field gets an increase of 15.7% in peak power density and a dramatically lowered polarization at high current density output.

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