Embossing of Aluminum LIGA Heat Exchangers and Lead Micro Regenerators

Cross-flow micro heat exchangers and regenerators of the type specified in this proposal offer great savings in applications where both heat transfer/unit volume or heat transfer/unit mass are important. While prototype micro cross-flow heat exchangers have been built from polymers and metals, the manufacturing methods used are prohibitively expensive for most applications. Presently, no one has shown the feasibility to mass-produce via molding (embossing) metal micro parts with heights of several hundred micrometers and aspect ratios (height/width) that are fairly high (five to ten). This proposal will test the premise that the surfaces of micro molds can be modified to make embossing of metal micro devices feasible. The result will be devices such as micro heat exchangers/regenerators made from metals such as aluminum and lead with superior performance. Specifically, a number of ceramic/metal coatings will be applied to LIGA molds with a variety of aspect ratios using a PVD/CVD system. Embossing experiments will be performed and the forces required to eject the parts as well as the quality of the parts will be quantified as a function of coating system.