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 - 83μW/cm2 and 3300μW/cm3, 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-100μW applications, especially in remote or hazardous conditions, where conventional powering units are hard to establish.

Original languageEnglish (US)
Pages (from-to)587-592
Number of pages6
JournalBiosensors and Bioelectronics
StatePublished - Nov 15 2014


  • Mass transfer
  • Micro-scale microbial fuel cell
  • Power density
  • Scaling effect

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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