Ethanol / Oxygene microfluidic biofuel cells

Abstract

This work presents the construction of an ethanol microfluidic biofuel cell (MBFC) based on bioelectrodes and operating in aY-shaped microfluidic channel. At the cathode, the oxygen is reduced by laccase, whereas at the anode, ethanol is oxidized by alcohol dehydroge- nase. The enzymes were immobilized in the presence of reactive species at gold electrode surfaces. Oxidant and Fuel streams move in parallel laminar flow without turbulent mixing into a microchannel. The benefit of the carbon nanoparticles with higher surface porosity was explained by the high porous structure that offered a closer proximity to the reactive species and improved diffusion of ethanol and oxygen within the enzyme films. The highercurrent and power densities were achieved for shorter and wider electrodes that allow for thinner boundary layer depletion at the electrodes surface resulting in efficient catalytic consumption of fuel and oxidant. This miniaturized device generated maximum power density of 90 μW cm-2 at 0.6 V for a flow rate 16 μL min^-1.