Figure 3

Power density, and polarization curves during the experiment for the OC (black lines), SMFC-1 (blue lines) and SMFC-2 (red lines). Power and density are shown for day 0 (a), day 46 (b), and day 96 (c). Polarization curves are shown for day 0 (d), day 46 (e), and day 96 (f). The dashed lines in (d–f) are the linear portion of the polarization curves used to determine the internal resistance.