An alternative is to use electroactive microbes that use extracellular electron transfer (EET) to transfer charge to, from and between external substrates like metals and even electrodes long distances, up to a centimeter from the cell surface with conductive pili, through specialized metalloprotein complexes that connect the cell surface to the electron transfer chain in the inner membrane and to metabolic reactions in the cytosol (Figure 1C) (REF_Sydow 2014).