“…Their low toxicity when compared to CH 3 OH, higher boiling points, and comparable energy density make them interesting candidates for electro-oxidation. Other reported fuels which also benefit from dense liquid phase storage and transportation include formic acid, ,− formate, ,− hydrogen peroxide (H 2 O 2 ), − sodium borohydride, − hydrazine, ,, and urea. , Many biofuels such as glucose and lactate have also been directly used as fuel or harvested from sample analytes. − Furthermore, some authors have explored the possibility of interchangeably feeding the same cell with different aforementioned fuels, proving the μFC capability of being fuel-flexible. ,, Maya-Cornejo et al showed a multifuel membraneless nanofluidic fuel cell based on Cu@Pd catalysts for the successful oxidation of methanol, ethanol, ethylene glycol, glycerol, and a mixture of fuels together (Figure a) . Lastly, some works have also utilized solid metals as anodes such as aluminum ,− or zinc …”