Water droplets and water columns are observed in the anode channels due to back diffusion. When the hydrogen flow rate is 70 mL/min, water columns could not move out from the gas channels. Because the vibration reduce the adhesion between the water and the supporting surface and increase the driving force, water columns can be moved easily under the mechanical vibration (amplitude is 4 mm, frequency is 20 Hz). In addition, the water droplets fluctuation for 20 Hz is great at the amplitude 4 mm compared with for 10 Hz and no vibration.