Captured photographs of monitoring dynamic flow of a eutectic Gallium-Indium liquid metal fluid through fluidic channel made of poly(dimethyl siloxane) (PDMS) on an organic light emitting board (OLEB). Schematics of the corresponding steps are also shown above the photographs. EL was not observed before injected fluid crossed over the underlying gap between two Indium tin oxide (ITO) parallel electrodes. (Step I and II) The light was turned on as soon as the fluid crossed over the gap and the advancing metallic fluid was clearly visualized with time. (Step III and IV) When a fluid was completely filled in the channel, the channel was fully visualized with the small break arising from the gap between the two parallel ITO electrodes. (Step IV) The alternating-current (AC) frequency was applied of 100 kHz to the device. The scale bar is 5 mm.