Figure 9.

Electrical switching behavior observed in a pressed powder pellet of melanin as published by the Santanto group. On the left the behavior of an apparent dry sample is shown and on the right a wet sample is shown. As can be seen, as the voltage is increased up to a threshold voltage V_T, the material enters a low resistance phase. Reprinted with permission from M. Raeli, A. Gouda, J. Bellemare et al., ACS Appl. Bio Mater., 2020, 3, 5244–5252 [105]. Copyright 2020 American Chemical Society.