Fabrication of a micro-direct methanol fuel cell using microfluidics

A direct-methanol fuel cell containing three parts: microchannels, electrodes, and a proton exchange membrane (PEM), was investigated. Nafion resin (NR) and polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (PS) were used as PEMs. Preparation of PEMs, including compositing with other polymers and their solubility, was performed and their proton conductivity was measured by a four point probe. The results showed that the 5 % Nafion resin has lower conductivity than the 5 % PS solution. The micro-fuel cell contained two acrylic channels, PEM, and two platinum catalyst electrodes on a silicon wafer. The assembled micro-fuel cells used 2 M methanol at the flow rate of 1.5 mL min^?1 in the anode channel and 5 × 10^?3 M KMnO₄ at the flow rate of 1.5 mL min^?1 in the cathode channel. The micro-fuel cell with the electrode distance of 300 ??m provided the power density of 59.16 ??W cm^?2 and the current density of 125.60 ??A cm^?2 at 0.47 V.