Producing Micro-Power with Microfluidic Enzymatic Biofuel Cells: A Comprehensive Review

Enzymatic biofuel cells (EBFCs) use enzymes as biocatalysts to produce clean energy. They have attracted much attention owing to several interesting features, such as the use of cheap and renewable biocatalysts, utilization of abundantly available high-energy-density biofuels, and their capability to operate under mild temperature and pH conditions. The integration of EBFCs into microfluidic architecture enables their application as small-scale power sources for portable, implantable, and wearable microelectronics. However, despite extensive research over the last two decades, this technology is still in the early stages of development owing to critical challenges, such as inefficient fuel oxidation, short lifetimes, and limited power density. This review paper broadly discusses various attributes of microfluidic EBFCs, focusing on the different microfabrication techniques employed to date because miniaturization is considered a promising approach for developing this technology. A short history and evolution of EBFCs are presented, after which fundamentals of the chemistry of EBFCs are briefly discussed to clarify the basic terms. In addition, various microfabrication techniques for manufacturing microfluidic EBFCs, which have been practiced over the last two decades, are reviewed thoroughly and compared according to resolution quality, fabrication convenience, and cost-effectiveness. Furthermore, potential applications of EBFCs and various obstacles to the realization of these applications are reviewed. Finally, the key challenges in producing practical and commercialized EBFCs and different approaches to overcome these challenges are discussed. This review article provides insight into the past, present, and future of this rapidly emerging microscale EBFC-based green technology.

Automated summary

Enzymatic biofuel cells (EBFCs) are a promising technology that utilizes enzymes as biocatalysts for clean energy production. Integrating EBFCs into microfluidic architecture allows for their application in portable, implantable, and wearable microelectronics. However, challenges such as inefficient fuel oxidation, short lifetimes, and limited power density hinder their development. This review comprehensively discusses the attributes, microfabrication techniques, potential applications, and challenges of microfluidic EBFCs, providing insights into the past, present, and future of this emerging green technology.