The primary focus of this Phase I SBIR program was on development of manufacturing methods for producing mechanically reliable and high performance solid oxide fuel cells operating at low temperatures (700 to 800{degrees}C). Specifically, NexTech Materials initiated development of low-cost tape casting, colloidal spray deposition, and co-sintering methods for preparing thin-film yttrium-stabilized zirconia (YSZ) electrolyte films on porous lanthanum strontium manganite (LSM) cathode substrates. Most of the work in Phase I was concentrated along two lines: (1) development of tape casting fabrication process resulting in controlled sintering shrinkage and porosity of the LSM cathode substrates; and (2) demonstration of a colloidal deposition and co-sintering methods for the targeted LSM/YSZ bi-layer structure. Additional work was performed to establish additional components of our overall approach, including the use of samarium-doped ceria as an interlayer - to prevent adverse reactions between LSM and YSZ and to enhance electrochemical reactions at the cathode/electrolyte interface. Feasibility was demonstrated by the successful fabrication of a dense YSZ electrolyte film on a porous LSM cathode substrate.