Effect of Non-Noble-Metal Electrode on Moisture-Enabled Electric Generator

Moisture-enabled electric generators (MEGs) are promising for harvesting energy from ambient humidity. However, using non-noble-metal electrodes changes the power generation driving force from the humidity gradient to metal oxidation. Experiments indicated that using carbon electrodes, in-thickness MEGs with wet tissue did not generate electricity. Employing Al, Fe, and Cu as top electrodes yielded of 0.78, 0.51, and 0.21 V output, respectively. TiO2-based in-plane MEGs show similar results. Using active electrodes also causes MEGs to lose humidity responsiveness. MEGs' research using active electrodes should differentiate the contribution of humidity and inevitable chemical reactions on power generation and consider the influence of metal corrosion on durability.