A Passive Vapor-Feed Direct Methanol Fuel Cell Based on a Composite Pervaporation Membrane

A passive micro direct methanol fuel cell (μDMFC) by using composite pervaporation membrane for vapor fuel supply without any extra power is presented. A simple and power free vaporizer, which consists of a polydimethylsiloxane (PDMS) active layer and a porous silicon support layer, is integrated with a μDMFC, converting the methanol from liquid phase to vapor phase. The novel anode vaporizer generates methanol vapor, which diffuses to and reacts with catalyst directly. The composite membranes with different parameters are prepared and tested to optimize the performance of the membrane vaporizer. The developed prototype exhibits a peak power density of 18.2 mW/cm² and a maximum fuel efficiency of 78.4% at room temperature. It is believed that the vapor-feed μDMFC will be more applicable for microsystems.