Sensors for alcohols can be fabricated using Direct Methanol Fuel Cell (DMFC) technology. The designed and fabrication of the sensor is by means of micro electro mechanical systems (MEMS) fabrication technology with microfludic interconnects and with the electrochemical inputs using a standard DMFC cell arrangement. An amperometric detection technique will be employed. The accuracy will be determined by the accurate detection of electric current or changes in electric current. Using a passive mode design protocol in COMSOL Multiphysics, we have optimized the overall power density and hence the sensitivity of the sensor. This was achieved using various physical parametric functions, and interfacing Darcy's law of fluidic flow through a porous medium, under specific pressure and temperature. This involved the fabrication of fluid flow diffusion layers using carbon matrix for electrodes. Pt-Sn was chosen as the Oxygen Reduction Reaction (ORR) catalysts. The cell outputs have been discussed.