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PNNL is developing a low-cost microfabrication process technology involving lamination and diffusion bonding of thin foil sections to form microchannel fluidics and gas flow components. The process is particularly well suited for fabrication of microscale energy and chemical systems, including microchannel chemical reactors, combustors, solvent separation units, heat exchangers, and fluid and gas flow systems. To date the laminated components have been fabricated from stainless steel, copper, and aluminum. With this method, perfectly smooth walled microchannels having virtually any aspect ratio or complex shape, can be fabricated with either an open edge or with the microchannels completely enclosed within a solid block of metal. Channel widths can be as small as 12 µm and have aspect ratios greater than 800. The diffusion bonding process forms a sealed monolithic unit. This concept is not limited to simple microchannel components. Components capable of mixing multiple materials with multiple fluid and gas flow paths can be fabricated just as easily as the simple single channel device. It is also possible to integrate membranes, catalysts, and coatings into the laminated components. Complex geometries are straightforward. Curved sections with curved channels to fit pipes or cylindrical reactor elements for localized heating and cooling can readily be fabricated. The fabrication process is mass production amenable, easily automated, and uses low cost materials.
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