Multi-material virtual prototyping for product development and biomedical engineering

This paper describes the development of a multi-material virtual prototyping (MMVP) system, which integrates virtual reality (VR) and layered manufacturing (LM) for digital fabrication of multi-material prototypes to facilitate advanced product development and biomedical engineering. The MMVP system incorporates a topological hierarchy-sorting algorithm, two algorithms for sequential and concurrent multi-toolpath planning, a build-time estimation algorithm, and a virtual prototyping system. Based on the topological hierarchy of slice contours, the sequential multi-toolpath planning algorithm generates sequential toolpaths that avoid redundant tool movements, while the concurrent multi-toolpath planning algorithm generates collision-free concurrent toolpaths to further reduce the build-time. To verify the resulting toolpaths and to facilitate estimation of fabrication cost, a mathematical model is incorporated for build-time estimation of multi-material fused deposition processes. The MMVP system is useful for planning, stereoscopic simulation, build-time estimation and validation of multi-toolpaths, and subsequent digital fabrication and analysis of multi-material prototypes. (C) 2006 Elsevier B.V. All rights reserved.