Miniaturised proton exchange fuel cell in micromachined silicon surface

The fabrication of porous electrocatalytic membranes with a wide surface plays an important role in the electrochemical technology for energy storage and bio-catalytic processes. One of the most promising systems for energy storage is the fuel cell: the miniaturisation of catalytic membranes and the development of materials with a high H2 content represent new challenges. The electrocatalytic reactions are generated in proximity of the surface where the catalyst elements are localised. For this reason it is necessary the use of porous material with a wide surface. Porous Si is characterised by a surface as wide as 200 m2 per cm3. Aim of this work is to show the feasibility to fabricate a suspended and autosupporting electrocatalytic sector, by using only surface micromachining processes compatible with the standard Si-based ULSI technology. This sector can be used for the realisation of miniaturised and Si-based proton exchange membrane fuel cell (PEMFC).