Invited: From PEM Fuel Cell Design to Biological Fuel Cells: The Status of Systems Development for Biological Fuel Cells

Over the last 10 years, there has been a wealth of development breakthroughs in the field of biological fuel cells (frequently called biofuel cells, BFCs) that have led to increased interest in the field. Researchers have improved the electron transfer between bioelectrocatalysts and electrode surfaces increasing current density(1, 2); the time, temperature, and pH stability of biological fuel cells(1, 3-6); the efficiency of the fuel cell by improving degree of oxidation(7-10), and the ability to implant into a variety of organisms (11-13). These advancements have led to the need for development of cell design to further improve electrochemical performance, meet form factor requirements, and decrease the volume and/or weight of the biological fuel cell, in order to improve the energy density. These design improvements range from advances in electrode material to thin-film, flexible fuel cell designs to microfluidics. All of these strategies will be detailed in this review.