title: Improved current and power density with a micro-scale microbial fuel cell due to a small characteristic length.
abstract: A microbial fuel cell (MFC) is a bio-electrochemical converter that can extract electricity from biomass by the catabolic reaction of microorganisms. This work demonstrates the impact of a small characteristic length in a Geobacteraceae-enriched, micro-scale microbial fuel cell (MFC) that achieved a high power density. The small characteristic length increased the surface-area-to-volume ratio (SAV) and the mass transfer coefficient. Together, these factors made it possible for the 100-µL MFC to achieve among the highest areal and volumetric power densities - 83 μW/cm(2) and 3300 μW/cm(3), respectively - among all micro-scale MFCs to date. Furthermore, the measured Coulombic efficiency (CE) was at least 79%, which is 2.5-fold greater than the previously reported maximum CE in micro-scale MFCs. The ability to improve these performance metrics may make micro-scale MFCs attractive for supplying power in sub-100 µW applications, especially in remote or hazardous conditions, where conventional powering units are hard to establish.
authors: School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, USA. Electronic address: hren12@asu.edu.
authors: Hao
authors: H
authors: Ren
authors: Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, Tempe, AZ, USA; School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA.
authors: César I
authors: CI
authors: Torres
authors: Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, Tempe, AZ, USA.
authors: Prathap
authors: P
authors: Parameswaran
authors: Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, Tempe, AZ, USA.
authors: Bruce E
authors: BE
authors: Rittmann
authors: School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, USA.
authors: Junseok
authors: J
authors: Chae
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004560:Electricity; D004867:Equipment Design; D045302:Geobacter / Q000502:physiology*; D008904:Miniaturization
keywords: Mass transfer; Micro-scale microbial fuel cell; Power density; Scaling effect