Abstract: A method for fabricating sub-millimeter sized parts uses electrodes created from patterned silicon wafers for electric-discharge machining (EDM), in which an electric discharge is generated between a patterned electrode and a conductive workpiece. Workpiece material corresponding to the electrode pattern is removed by electroerosion, and the remaining workpiece contains the desired part. Electrodes are formed by etching stepped patterns in silicon wafers and depositing a thin metallic layer on the wafer. The resulting electrode is used in an EDM machine, and an inverse pattern is produced in the part. Alternately, the silicon wafer pattern is filled by a metal to produce a metal electrode with an inverse pattern. The wafer is removed from the metal, and the metal is used in an EDM machine. The resulting part has the same pattern as the silicon wafer used to create the metal electrode.

Abstract: Micro-Mold Shape Deposition Manufacturing (&mgr;-Mold SDM) is a method for fabricating complex, three-dimensional microstructures from layered silicon molds. Silicon wafers are etched using conventional silicon-processing techniques to produce wafers with surface patterns, some of which contain through-etched regions. The wafers are then stacked and bonded together to form a mold, which is filled with part material. In one embodiment, the part material is a ceramic or metallic gelcasting slurry that is poured into the mold and solidified to form a part precursor. The mold is removed, and the precursor is sintered to form the final part. The gelcasting material may also be a polymer or magnetic slurry, in which case sintering is not needed. The mold can also be filled by electroplating a metal into it; if necessary, each layer is filled with metal after being bonded to a previously filled layer.