The fabrication of a microchannel chemical solvent separation unit and a microchannel chemical reactor is described. The performance of the solvent separation unit was enhanced by improved kinetic effects resulting from short liquid/liquid contact times in the device. These effects were exploited to allow preferential extraction of solute species from a fluid waste stream. The completed unit consisted of a series of microchannels separated by micromachined metal or polyimide membranes. Channel and membrane layers were produced from individual layers of type 304 stainless steel shim. Laser micromachining, photochemical machining, and photolithographic patterning were used to fabricate the individual layers. Flow channel width, height and length was 100 mu m, 1 cm, and 8 cm respectively. The channels had an aspect ratio of 1000. The separation membranes consisted of an array of 5-mu m to 30-mu m-diameter micropores laser micromachined in polyimide or 130 mu m diameter micropores machined through the stainless steel shim using photochemical etching. Microscale catalytic and mass transfer reactions were employed by the chemical reactor to achieve high efficiency partial oxidation reactions and conversion of methane to syngas. The chemical reactor was fabricated from laminated stainless steel, and consisted of four microchannel chambers with a combustion section. The reactor successfully operated at temperatures near 900 degrees C.