Recent progress in mitochondrial biofuel cells

As power factories of organisms, mitochondrial produce electron transfer chains during the production of energetic adenosine triphosphate, which is ingeniously developed as fuel cells. The emerging mitochondrial biofuel cells (MBFCs), with whole mitochondria or mitochondrial enzymes as catalysts, may be a promising power supply for wearable and implantable biomedical devices. Currently, those devices still use traditional batteries and capacitors, which raises concerns regarding biocompatibility, adverse reactions caused by mechanical mismatch, and the need for repetitive charging. In addition, MBFCs can be utilized to harvest chemical energy from biological systems or waste. In this article, we detail the working principles of MBFCs, particularly emphasizing the electron transport chains of mitochondrial that are the basics of fuel cells. Based on the structure of biofuel cells and the latest developments, we comparably discuss the design strategies for individual components of MBFCs, including catalysts, cofactors, and electrodes. Finally, current challenges and future perspectives are discussed. This work aims to provide a comprehensive view of MBFCs to whom working in this area.