Next, we examined and engineered the wicking properties of our channel architectures in various flow configurations, since effective wetting within the porous LIG-E structure is essential to maximizing electrode utilization for sensing applications. The wetting properties of laser-pyrolyzed polyimide can be tuned by control of the lasing atmosphere ( ), KMnO4 pre-treatment , and post-modifications . In our cellulose systems, we found that the laser-pyrolyzed electrodes are always superhydrophilic, completely absorbing a water droplet within < 50 ms. This is comparable to unmodified cellulose paper (Fig. ) regardless of the lasing atmosphere (Fig. ). It should be noted that we used "wetting time" to evaluate hydrophilicity since water contact angles cannot be measured on wicking substrates.