title: Microfluidic biofuel cells: the influence of electrode diffusion layer on performance.
abstract: Microfluidic biofuel cells exploit the lack of convective mixing at low Reynolds number to eliminate the need for a physical membrane to separate fuel from oxidant. This paper demonstrates how the length and spacing of electrodes within a microchannel, and thus thickness of the diffusion layer, affects the performance of a microfluidic biofuel cell. It was found that splitting a single electrode into two (or more) smaller electrodes and separating them by a distance equal to three times their length prevents the continuous increase in thickness of a diffusion layer. This change results in a 25% increase in maximum power density compared to a single electrode device with identical electroactive area. Furthermore, we found that the maximum current density of a microfluidic biofuel cell operated with different electrode configurations (i.e., length of cathode) closely matches that predicted by theory.
authors.affiliation: Division of Engineering, Brown University, Providence, RI 02912, USA.
authors.forename: Keng Guan
authors.initials: KG
authors.lastname: Lim
authors.forename: G Tayhas R
authors.initials: GT
authors.lastname: Palmore
mesh_terms: D001674:Bioelectric Energy Sources; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods