Microfabrication and characterization of a silicon-based millimeter scale, PEM fuel cell operating with hydrogen, methanol, or formic acid

A silicon-based microfabricated fuel cell has been developed to provide a high energy and power density power source on the millimeter size scale. An integrated silicon microscale membrane electrode assembly (Si-μMEA) consisting of a Nafion 112™ membrane bonded between two electrodes on microstructured silicon substrates forms the core element of this polymer electrolyte membrane fuel cell. The use of silicon meshes that serve the purpose of catalyst support, current collector, and structural element provides a promising alternative to the traditional gas diffusion layer-based MEAs for the development of robust, high-performance microfuel cells. The cell performance was characterized using hydrogen, methanol, and concentrated formic acid-water fuels at the anode, and oxygen at the cathode. The catalyst used for each fuel was Pt black. Preliminary results show that the microfabricated fuel cell running on formic acid may be a promising alternative for fuel cell applications running at ambient temperature and pressure, provided additional work on catalyst improvement, assembly, and packaging is performed so that the power density achieves that of traditional forced fed PEM fuel cell design.