Design and Development of micro DMFC with selective sensor materials

Abstract

Ampherometric sensors can be developed for volatile substances like alcohols using Direct Methanol Fuel Cell (DMFC) technology. The objective of this work is to develop low-cost electrocatalyst materials for improved oxygen reduction reaction (ORR) and suitable methods of preparing electrodes that will lead to overall cost reduction of the sensing electrode. Among other Pt alloys, Pt-Sn exhibits high sensitivity in ORR and hence will be used as the ORR catalysts. The current density of the chemically synthesised Pt-Sn/C was analysed for various concentration of methanol. To design the sensor, a passive mode design protocol in COMSOL Multiphysics has been used. The design and simulation involved optimization of many parameters, in the construction of the cell. The parameters were optimised for a 1.0 cm² cell area, interfacing Darcy’s law of fluidic flow through a porous medium, under specific pressure and temperature conditions. The design and fabrication of the sensor was by means of micro electro mechanical systems (MEMS) technology with the electrochemical inputs using a standard DMFC single cell arrangement. A 3- D printing technique was used to fabricate the cell structure with microfluidic inter connections. The output of the cell was optimized for ampherometric detection. The sensor response characteristics were studied and will be presented.