Mass manufacturing commonly assembles single material parts in post-production. In contrast, digital fabrication and multimaterial additive techniques are beginning to introduce specificity, customization, and material integration into product design. This concept, referred to as tunability, makes it possible for designs to be adapted to their functional goal or environment. Instead of assembling single materials discretely, 3D printing can produce graded material properties with tunable characteristics such as color, density, and stiffness. In the previous chaise lounge example, the functional goal was acoustical. For the environmental case, we used sensed data alongside design algorithms to create a computational model. Another example is seen in a customized 3D printed helmet for a specific person’s head, designed by a team led by Dr. Neri Oxman.[—] As opposed to a mass manufacturing approach based on a generic user, 3D printing enables tailored, highly customized design both in terms of geometry and material property variation. For the helmet, user data from a medical head scan allowed for the external geometry and internal material distribution of the head to be mapped, as presented in Figure 18-12. The helmet was designed and 3D printed with variable stiffness properties on a Stratasys Objet500 Connex 3D printer. The helmet model is algorithmically generated to provide a geometrical fit that provides different elastic responses corresponding to the layout of tissue and bone in the user’s head.
Figure 18-11. The Gemini Acoustic Chaise was 3D printed on a Stratasys Objet500 Connex3 3D printer and mounted on a CNC milled wood back (Le Laboratoire). Designed by Dr. Neri Oxman in collaboration with Stratasys and Dr. W. Craig Carter (MIT). Image credit: Michel Figuet (top) and Yoram Reshef (bottom).
Through these gradients of elasticity, the helmet provides improved function and feel. In this sense, 3D printing introduces a new era of customized fit and functionality for individual users and environments. The final helmet is printed on the Stratasys machine and is exhibited as the Minotaur Head with Lamella.
Figure 18-12. Minotaur Head with Lamella. From the Imaginary Being series, Centre Pompidou (Paris). 3D printed by Stratasys with variable stiffness properties on a Objet500 Connex 3D printer. Designed by Dr. Neri Oxman in collaboration with Dr. W. Craig Carter (MIT), Joe Hicklin (The Mathworks), and Turlif Vilbrandt (Uformia). Photo
credit: Yoram Reshef.
The future of 3D printing is moving toward increased control of multimaterial printers. In time, additional printing techniques will be developed or converted to output multiple materials. Multimaterial printing control allows for functional gradient properties to accommodate functional goals and environmental data. For now, the field is limited primarily to optically cured polymers. These polymers work well for prototypes, but due to the higher cost, long-term stability issues, and material properties, additional material types is a forthcoming challenge and will be developed in future technologies. We believe multimaterial metal/thermoplastic printers, digital electronics printers, and biological material printers are on the near horizon.