The first generation of multimaterial 3D printers have been commercially available for a few years now. In January 2014, Stratasys unveiled the world's first color multimaterial 3D printer. In January 2015, Voxel8 unveiled a printer capable of creating objects with both electrically conductive and insulating material. In 2016, Hewlett Packard intend to release the MultiJet Fusion range of 3D printers. All of these multimaterial 3D printers allow different materials to be used in the creation of a single object beyond just support material. For an in-depth analysis of all 3D printing markets, see 3D Printing 2015-2025: Technologies, Markets, Players.
Interesting research has already been done using these multimaterial 3D printers. Transparent and opaque materials have been used to create light guides that can be used to convey signals optically (like an optic fibre) through a 3D printed case. Other research has used multimaterial printers to create graded materials that can have variable rigidity, from bendy at one end to rigid at the other. Multimaterial 3D printing has also been used to create metamaterials: artificial structures that have properties unlike any natural material. The possibilities for multimaterial 3D printing are endless and, in the long term, multimaterial will undoubtedly be the one of the most revolutionary concepts in the world of additive manufacturing.
Most of the interesting developments achieved using multimaterial 3D printing have required a paradigm shift in design software. This fundamental change is within the reach of dedicated researchers but there is a substantial gap between the traditional CAD tools widely used by designers today and the next generation tools that designers would have to be familiar with before they can hope to fully leverage multimaterial 3D printing.
The new challenges facing designers targeting 3D printers are most elegantly solved by adopting a declarative approach to CAD. Traditionally, most designs are created by a designer laying out geometric elements in order to achieve what they believe is an appropriate shape. For mechanical applications Finite Element Modeling (FEM) simulations are used to predict the stresses and strains on a designed part in order to test and improve a design before it goes into manufacture. Computing power has only relatively recently advanced to the point where the feedback from a FEM simulation can be applied automatically to a design in order to iterate towards the perfect design. This leads to a more declarative approach to design where the designer specifies the problem rather than the solution and the computer is responsible for finding its own solution in the form of the ideal object.
The paradigm shift that designers will have to make in order to fully leverage multimaterial 3D printing is in many ways reminiscent of the shift to declarative programming in the software industry. Researchers in academia solved the core problems and laid the foundation for declarative programming and industry later adopted the approach, partly due to the emergence of multicore computers in 2005. Given the seemingly fast paced nature of software it is surprising that it took around 40 years for these academic ideas to be widely adopted in industry. If the equivalent change in the design world takes a comparable amount of time then multimaterial 3D printing will be a slow-burning revolution.
For more information about the 3D printing industry including technologies, materials, visualizations of the landscape of 3D printers in terms of price, speed, build volume, precision and other metrics and 10 year market forecasts read 3D Printing 2015-2025: Technologies, Markets, Players
Top image: Stratasys
