TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Parameters: The bipolar plate is 50-2000 (preferably 500-1000) mum thick. The flow channels are 1-5000 (preferably 20-500) mum wide and 1-3000 (preferably 5-500) mum deep. Preferred Components: The semiconductive body is Group IV semiconductors, Group III-V semiconductors, or Group II-VI semiconductors. It is a doped semiconductor. It can be silicon. The first flow channel is further coated with reforming catalyst of catalytic combustor. The bipolar plate further comprises a conduit for receiving cooling or heating fluid, and a recuperative heat exchanger. The conduit is further coated with a reforming catalyst or catalytic combustor. The bipolar plate further comprises resistive element within the bulk of the bipolar plate or on the surface of the bipolar plate and to heat the bipolar plate. The resistive element is thin film resistive element, thick film resistive elements, or diffused resistors. The bipolar plate further includes sensor, which can be mechanical, thermal, magnetic, electrical, chemical, or radiation sensors. The sensor can also be pressure, temperature, voltage, or flow sensors. The chemical sensor can be hydrogen ion, hydrogen, oxygen, water, hydrogen peroxide, carbon monoxide, carbon dioxide, sulfur, sulfur oxide, methanol, ethanol, methane, butane, propane or pentane sensor. The substrate is semiconductors, graphite or metals. Preferred Method: The etching is performed by using an etchant, which can be wet anisotropic etchants, wet isotropic etchants, plasma anisotropic etchants, and/or plasma isotropic etchants. A mask is applied to the first or second face of the substrate before the etching step. It is patterned by photolithography before the step of etching the flow channel from the first or second face. The first channel is coated with reforming catalyst. A conduit that passes through the substrate is created by performing an etching and bonding. The conduit may be made by drilling, abrasive machining, laser machining, and laser ablation. A sensor is micromachined on the surface of the substrate. The making of resistive element and the micromachining of the sensor is made by photolithography, wet etching, plasma etching, ion implantation, high temperature diffusion, boron concentration dependent etching, electrochemical etching, bonding, lift off, spin coating, dip coating, sputter deposition, evaporation, electroplating, solution deposition or chemical vapor deposition.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The reforming catalyst is platinum, ruthenium, rhodium, nickel, cerium, iron chromium, cobalt, manganese, copper, aluminum, and/or their oxides. The resistive element is silicon, nickel, chromium, tantalum, aluminum, molybdenum, tungsten, titanium, palladium, platinum, their silicides, and/or their oxides.