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Katherine T. Faber, Northwestern University, DMR 0710630Biomorphic ceramics are made from natural materials, such as wood, and retain the porous honeycomb structure of the precursor. Electrodeposition, used in the fabrication of circuit board interconnects, is a low-temperature, non-reactive method of infiltrating porous ceramic scaffolds to create composites of biomorphic graphite and copper. However, the large size scale and high aspect ratio of channels in these scaffolds, compared to interconnects, limit the usefulness of industry protocols and plating models. Existing models fail to predict the observed surface choke-off seen in large channels.

A transport- and adsorption-limited model of the electrolyte species, including the movement of the Cu2+ ions in the channel, was developed to replicate this observed plating profile shape and explain the shift in ideal plating conditions between interconnects and biomorphic scaffolds. Shown at the top right is a 3D X-ray reconstruction of copper plating in porous graphite, showing a dense layer of copper at the surface that prevents further plating of the channels. By considering the copper ion depletion in the center of the channel (middle), it is possible to predict accurate growth profiles (bottom), which can be used, along with the experi-mental parameters, to determine the plating conditions for optimal filling.

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An integral part of successful research requires the technical collaboration between scientists with various expertise. The Materials World Network (MWN) Program is particularly useful in promoting teamwork and fostering partnerships between various institutions. Even under the umbrella of a single research project, collaborations are sought for each step to promote discussion, creativity, and thoroughness in the investigation. Among the partnerships formed for the study of biomorphic graphite/copper composites at Northwestern University are: the University of Seville for the electrodeposition model to predict ideal filling in of channels; Oak Ridge National Laboratory for thermal conductivity measurements; and Argonne National Lab for the study of mechanical properties and load transfer between graphite/copper phases using synchrotron radiation at the Advanced Photon Source.

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Materials World Networking: The Research TeamKatherine T. Faber, Northwestern University, DMR 0710630