In a lateral flow format (Fig. ), LIG-E acts as a flow delay compared to neat paper (51±4 s delay for a 4 mm long electrode, Fig. ) because its deep structure is hydrophobic . Treatment of the LIG-E with oxygen plasma (before the wax patterning step) induces capillary-driven lateral flows similar to that of cellulose paper (Fig. ), likely due to the introduction of hydrophilic oxygen-rich moieties on graphenic surfaces . On the other hand, in a vertical flow configuration (Fig. ), the LIG-E exhibits unobstructed capillary flow irrespective of oxygen plasma treatment (Fig. ). This result agrees with the contact angle measurements. We fitted the capillary front profile using the Washburn equation according to 𝐿 = (𝐷 𝑤 • 𝑡) 0.5 where L is the front position, DW is the Washburn diffusion coefficient and t is time . We found that the LIG-E diffusion coefficient in lateral flow reduces approximately by six-fold compared to untreated paper or plasma-treated LIG-E (Fig. ).