Solid oxide electrolyte membranes of sputter deposited yttria-stablized zirconia (YSZ) were integrated in silicon technology for applications in micro power generators fuelled by hydrogen or H2+CO. An electrochemically deposited nickel grid was used as mechanical support for the 200-300 nm thick membrane. Cells with 0.5 to 5 mm diameter were fabricated showing mechanical stability up to 650 °C. The ionic conduction becomes sufficient to produce open circuit voltage (OCV) above 380 °C. An OCV of 850 mV was achieved at 550 °C in an H2/Ar fuel mixture using porous Pt electrodes.