TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The coarsely porous support is embedded within the first electrode layer. The electrolyte layer is bonded along its periphery to the non-porous frame. The internal shape of the non-porous frame is rectangular, square, non-rectangular, pentagonal, round, or ovoid. The non-porous frame contains coarsely porous supports. The coarsely porous support is shaped to fit within the corresponding non-porous frame. The nonporous frame is provided with a recess in which the coarsely porous support is located. The coarsely porous support is physically bonded along its periphery to the non-porous stainless steel frame. It is an expanded foil (9) of stainless steel, or an expanded foil bound by solid regions at two opposite ends and joined to side strips at the other two opposite sides. The expanded foil includes through apertures fluidly interconnecting the one and other surfaces of the expanded foil; or an array of expanded region with intervening solid strips bound by side strips at opposite sides. The number of through apertures is 1000-12000 (preferably 7000)/in2 (1.55x106-1.86x107 (preferably 1.09x107)/m2).The open area provided by the apertures is 30-90 (preferably 70)% of the total area of the porous support. The expanded region includes a recess in which the first electrode layer is at least partially located. The expanded foil is produced in a continuous process to have a single or an array of expanded regions with intervening solid regions bound by side strips at opposite sides. The coarsely porous support contains two or more layers of woven meshes, where a first mesh layer is located on the fuel cell side of the substrate and a second or more mesh layer(s) is the layer reinforcing the preceding mesh layer(s) and located on the other side of the substrate. The first mesh layer is the woven mesh. The first and the second electrode layers are sintered materials containing a porosity fraction of 20-50 (preferably 30-40) vol.%.The first electrode layer is a single layer in which the coarsely porous support is embedded to provide structural support. It comprises two sub-layers comprising a first sub-layer located under the electrolyte layer and a second sub-layer located under the first sub-layer. The second sub-layer is the layer in which the coarsely porous support is embedded to provide structural support. The first sub-layer is 60-80 (preferably 70) vol.% dense. The second sub-layer is 50-70 (preferably 60) vol.% dense. The first electrode layer is provided as an anode or cathode layer of the fuel cell. The second electrode is provided as a cathode or anode layer of the fuel cell. The electrolyte layer is sintered at or below 1000 degrees Celsius and at least 97 vol.% dense. It comprises a dense impermeable layer of a gadolinia-doped ceria. An array of electro-catalytically active membranes each comprising an anode layer, an electrolyte layer and a cathode layer are provided upon each type of the stainless steel substrates. The substrate is planar, curved or tubular. It is for a fuel cell, an oxygen converter, or a half cell having the substrate and the electrolyte layer.Preferred Properties: The non-porous frame has a thickness of 50 mum to 2 mm, preferably 100-300 mum. The coarsely porous support has a thickness of one half-2/3 of the thickness of the stainless steel frame. The expanded foil outside the recess has a thickness of 50 mum to 2 mm, preferably 100 mum). The recess has a depth of 5-30 (preferably 20) mum. The first electrode layer has a thickness equivalent to that of the surrounding non-porous frame section of the substrate. The second electrode layer has a thickness of 5-50 (preferably 5-15) mum. The first sub-layer has a thickness of 5-30 (preferably 5-15) mum. The thickness of the second sub-layer takes a value to make the total thickness of the first and the second sub-layers equivalent to that of the surrounding non-porous frame section. The electrolyte layer has a thickness of 5-30 (preferably 10-20) mum.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The anode layer comprises nickel oxide (40-60, preferably 50 vol.%), and correspondingly rare earth-doped ceria (60-40, preferably 50 vol.%). The cathode layer comprises a sintered powder mixture of rare earth-doped ceria and a perovskite oxide mixed conductor. The perovskite oxide mixed conductor comprises La1-xSrxCoyFe1-yO3-delta. The rare earth-doped ceria comprises Ce1-xGdxO3-x/2, preferably Ce0.9Gd0.1O1.95. The gadolinia-doped ceria comprises Cel-xGdxO3-x, preferably Ce0.9Gd0.1O1.95.x (for perovskite) = at least 0.5 and at most 0.2;y = at least 1 and at most 0.2;x (for rare earth-doped ceria) = at least 0.32 and at most 0.1;andx (for gadolinia-doped ceria) = at least 0.3 and at most 0.1.    TECHNOLOGY FOCUS - METALLURGY - Preferred Material: The coarsely porous support is produced from a suitably woven mesh of a stainless steel wire.Preferred Component: The stainless steel used for the substrates is a ferritic stainless steel; or a titanium/niobium stabilized ferritic stainless steel containing chromium (17.5-22.0 wt.%), manganese (0.3-1.0 wt.%) and aluminum (less than 0.2 wt.%).Preferred Properties: The cross-sectional dimensions of the stainless steel wire has a wire diameter that is the average of the diagonal lengths measurable through the center of symmetry of the wire cross-section. The stainless steel wire has a wire diameter of 5-200 (preferably 50) mum. The second or more layers of the woven mesh have a wire diameter of at least twice that of the first mesh layer. The first and second mesh layers have a total thickness of one half-2/3 of the thickness of the surrounding section of the non-porous frame.