Proton exchange membrane and bio-Fenton micro fuel cells for energy harvesting, gas leakage detection, and dye degradation

The present work focuses on the non-conventional design and operation of micro fuel cells. Two different kinds of fuel cells, Proton Exchange Membrane (PEM) and Biological Fenton (BF) based fuel cells, are fabricated to harvest energy. For the PEM fuel cell, H<inf>2</inf>and O<inf>2</inf>are generated by Mg/HCl reaction and Fenton's reaction respectively, and are subsequently fed into two terminals of the PEM fuel cell. For the BF fuel cell, the reaction product of hemoglobin (Hb) with hydrogen peroxide (H<inf>2</inf>O<inf>2</inf>) is used as a source of chemical fuel to generate electrical energy within the fuel cell. An array of PEM microscale fuel cells is fabricated to scale up the reaction which can be used for MEMS/NEMS applications. Furthermore, the application of this adhesive and flexible PEM fuel cell as a hydrogen leakage sensor is demonstrated. In the BF fuel cell, an electronic imbalance across a carbon tape is generated owing to the formation of reactive hydroxyl radicals and concurrent electrons in the system. The generation of a highly oxidizing hydroxyl radical is also utilized to degrade Methylene Blue (MB) dye along with energy harvesting. This multi-purpose fuel cell can be synergistically used in industrial applications of waste treatment as well as energy production.