Understanding the coupled two-phase dynamics in the cathode gas diffusion layer (GDL) and gas channel (GC) is of vital importance to optimize water management and to improve performance of proton exchange membrane fuel cell (PEMFC). However, it is difficult to directly observe the two-phase flow in the cathode of PEMFC because the GDL is opaque and has complex structures. To circumvent this issue, a similarity experiment model is developed in the present study. Based on the soft lithography technology, we fabricate a microfluidic device composed of a duct representing the GC and a bundle of tubes representing the GDL. Emergence of liquid droplets from these tubes into the duct gas stream is conducted to mimic the two-phase dynamics in the GDL and the GC. With this similarity experiment, we explore the influences of the gas flow rate on the liquid water flow in the cathode of PEMFC as well as the effects of the GDL surface defects on the two-phase dynamics in the GC. The two-phase flows in the hydrophilic and hydrophobic systems are also compared to elucidate the effects of wettability on water management of PEMFCs. (C) 2014 Elsevier Ltd. All rights reserved.