A Paper-Based Microfluidic Fuel Cell Using Soft Drinks as a Renewable Energy Source

The research aims were to construct an air-breathing paper-based microfluidic fuel cell (paper-based muFC) and to evaluated it with different soft drinks to provide energy for their prospective use in portable devices as an emergency power source. First, in a half-cell configuration, cyclic voltammetry showed that glucose, maltose, and fructose had specific oxidation zones in the presence of platinum-ruthenium on carbon (PtRu/C) when they were individual. Still, when they were mixed, glucose was observed to be oxidized to a greater extent than fructose and maltose. After, when a paper-based muFC was constructed, PtRu/C and platinum on carbon (Pt/C) were used as anode and cathode, the performance of this muFC was mostly influenced by the concentration of glucose present in each soft drink, obtaining maximum power densities at room temperature of 0.061, 0.063, 0.060, and 0.073 mW cm-2 for Coca Cola(R), Pepsi(R), Dr. Pepper(R), and 7up(R), respectively. Interestingly, when the soft drinks were cooled, the performance was increased up to 85%. Furthermore, a four-cell stack muFC was constructed to demonstrate its usefulness as a possible power supply, obtaining a power density of 0.4 mW cm-2, using Coca Cola(R) as fuel and air as oxidant. Together, the results of the present study indicate an alternative application of an muFC using soft drinks as a backup source of energy in emergencies.