It is proposed to develop a simple and clear language for use as a digital interface in Solid Free-Form Fabrication. This language is called "SIF" for "Solid Interchange Format" inspired by CIF, the Caltech Intermediate Form for LSI layout description. The role of SIF would be to describe the ideal solid part desired, in a fabrication-process-independent way. It is further proposed to create a foundation for some of the key tools needed with such an exchange language, in particular, a robust slicing tool to create 2.5D layers needed for process planning, as well as checker programs that will verify that the shape specified in the SIF file is indeed a closed solid, has the required topological and geometric properties, and specifies only realizable features containing certain minimum feature sizes and separations. Finally, it is proposed to develop test structures of various kinds that will test the robustness of analysis and conversion tools working from SIF input for different SFF fabrication processes and to monitor the quality of individual production runs.
