A novel lateral venting structure for high-efficiency gas-liquid separation in paper-based microfluidic fuel cell

Paper-based microfluidic fuel cells powered by capillary action combine low cost, high sensitivity, and a compact design, offering strong potential for portable and single-use electronic devices. However, the accumulation of gas byproducts can hinder mass transfer and reduce electrochemical efficiency, leading to performance degradation and instability. To address this challenge, this study proposes a novel arrangement of lateral venting microchannels to accelerate gas removal and achieve efficient gas–liquid separation. The model is validated by experimental data. The results demonstrate that the venting structure enhances fuel utilization and markedly improves performance, particularly under medium to high current densities. In the optimized configuration, the gas removal rate reaches 44.48 % and the peak power density increases to 45.81 mW/cm2, representing a substantial improvement over conventional design. These findings confirm that reasonable exhaust channel design can effectively mitigate gas-induced performance losses, providing not only an effective solution for gas management in paper-based microfluidic fuel cells but also a more reliable and efficient theoretical basis and practical approach for their engineering applications in portable electronics and biosensors.