Additive manufacturing (AM) technologies has brought unprecedented freedom to the fabrication of functional parts with high complex, multi-material and gradient density structure. However, currently only traditional design methods are available for AM design process, which do not take full advantage of AM capabilities. Therefore, a new design method with the consideration of all aspects of AM advantages is urgently in need. A detailed literature review on traditional design methods is presented with focused attention on the potential of using these methods to design functional parts for additive manufacturing processes. Based on thorough understanding and comparison of current structure design methods, a new design approach that integrates topological and functional optimizations for AM products is presented. With this method, an essential link is established between topological optimization result and various functional parameters of complex structure. Parts can be designed in multi levels for multi functions simultaneously. This design method provides an important foundation for future research on designing AM products with improved multiple functions and optimized topology.
