Tubular solid oxide fuel cells (SOFCs) have many desirable advantages compared to other SOFC applications. Recently, micro-tubular SOFCs were studied to apply them into APU systems for future vehicles. In this study, electrochemical properties of the micro-tubular SOFCs (1.6 mm O.D.) have been characterized. Electrochemical analysis showed excellent performance with a maximum power density of 1.3 W/cm(2) at 550 degrees C. The impedance information gained at cell operating temperatures of 450, 500, and 550 degrees C showed individual cell ohmic resistances of 1.0, 0.6, and 0.2 Omega respectively. Within the operating temperature range of 450-550 degrees C, the ceria based micro-tubular SOFCs (cathode length: 8 mm) were found to have power densities ranging between 0.263 and 1.310 W/cm(2). The mechanical properties of the tubes were also analyzed through internal burst testing and monotonic compressive loading on a c-ring test specimen. The two testing techniques are compared and related, and maximum hoop stress values are reported for each of the fabrication parameters. This study showed feasible electrochemical properties and mechanical strength of micro-tubular SOFC for APU applications. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.