A simplified solid oxide fuel cell (SOFC) design has been developed that would eliminate the need for external sealants yet maintains the hermetic requirements necessary for separation of fuel from oxidant. This hermetic seat is based on the formation of a solid-state interface, between the electrolyte and the interconnect. The novel SOFC design eliminates unnecessary interface formation and material addition, thus greatly simplifying fuel cell stacks. Overcasting and co-casting techniques were used to fabricate symmetric cell and lateral geometries in order to examine the interfacial characteristics of the hermetic structure and particularly the solid-state seal. Leakage rates determined from mass spectrometry were about 4.57*10(-7) L/s at 750 degrees C. (c) 2005 Elsevier B.V. All rights reserved.