TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The first and second fluids contact each other to define an interface as the first and second fluids laminarly flow within the channel or plenum. A separator is positioned between the first fluid laminarly flowing adjacent the first electrode and the second fluid laminarly flowing adjacent the second electrode. The separator is a metallic membrane or a polymeric membrane. The first and second flow directions range from perpendicular to each other to parallel to each other. The first fluid laminarly flowing adjacent the first electrode has a first flow velocity. The second fluid laminarly flowing adjacent the second electrode has a second flow velocity. The first and second flow velocities are different from each other.The first electrode is an anode (116). The second electrode is a cathode (120). The first fluid is a liquid fuel/electrolyte mixture (112). The second fluid is a liquid oxidant/electrolyte mixture (114). A third fluid laminarly flows between the first and second fluids laminarly flowing within the channel or plenum. The third fluid laminarly flows in a third flow direction that is optionally the same as the first flow direction. It has a third flow velocity that is optionally the same as the first flow velocity. At least one of the first and second electrodes includes passageways that extend through the electrode.Preferred Dimensions: At least one of the first and second electrodes has a thickness of 300-500 microns. The channel or plenum has a thickness of 50 microns to 1 mm.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The oxidant is oxygen, hydrogen peroxide and/or nitric acid. The electrolyte is phosphoric acid or sulfuric acid. At least one of the first and second electrodes is composed of silicon.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Materials: The fuel is methanol, ethanol and/or propanol. The electrolyte may be trifluoromethane sulfonic acid, difluoromethane diphosphonic acid, difluoromethane disulfonic acid, or trifluoroacetic acid.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Materials: The oxidant is oxygen, hydrogen peroxide and/or nitric acid. The electrolyte is phosphoric acid or sulfuric acid. At least one of the first and second electrodes is composed of silicon.