New design software simplifies multi-material 3D printing

One of the challenges of additive manufacturing is designing and 3D printing objects with many different materials or mixtures of materials. However, a team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) believes it has found a solution with a new user-friendly interface.

Known as “Foundry”, the team developed the system for custom-designing a variety of 3D printed objects with multiple materials.

Foundry’s interface makes it easier for non-engineers to create their own designs for 3-D printed objects such as bike seats. (Image courtesy of Kiril Vidimče/MIT CSAIL)

“In traditional manufacturing, objects made of different materials are manufactured via separate processes and then assembled with an adhesive or another binding process,” says PhD student Kiril Vidimče, who is first author on the paper. “Even existing multi-material 3D printers have a similar workflow: parts are designed in traditional CAD [computer-aided-design] systems one at a time and then the print software allows the user to assign a single material to each part.”

However, Foundry operates differently. Users are able to vary the material properties at a very fine resolution. Vidimče explains that the program is like Photoshop for 3D printed materials, allowing the user to design object made of new composite materials with optimal properties for any given project.

The team has used the interface to design and 3D print a number of objects including a ping-pong paddle, skis with retro-reflective surfaces, a tricycle wheel, a helmet, and even a bone that could someday be used for surgical planning.

Foundry was developed out of the challenges engineers face when redesigning multi-material objects with existing design tools. Even for experienced engineers, the process could take many days with some designs completely infeasible. The new user-friend interface enables users to create these designs quickly and easily.

“3D printing is about more than just clicking a button and seeing the product,” Vidimče says. “It’s about printing things that can’t currently be made with traditional manufacturing.”

A multi-material ping-pong paddle fabricated with Foundry. (Image courtesy of Kiril Vidimče/MIT CSAIL).

Foundry serves as the interface to help create multi-material objects. To use it, you first design your object in a traditional CAD package like SolidWorks. Once the file is exported, you can determine the object’s composition by creating an “operator graph” that can include any of approximately 100 fine-tuned actions called “operators.”

Operators can “subdivide,” “remap,” or “assign” materials. Some operators cleanly divide an object into two or more different materials, while others provide more of a gradual shift from one material to another.

The interfaces allow users to mix and match any combination of materials and also assign specific properties to different parts of the object. The design can be previewed in real-time, rather than having to wait until the final steps of the printing process.

Using Foundry to exploit the full capabilities of the 3D printing platform enables many practical applications in many different industries including the medical device market. For example, surgeons could create high-quality replicas of objects like bones to practice on, while doctors could also develop more comfortable dentures and other products that would benefit from having both soft and rigid components.

Vidimče’s hope for Foundry is to create a community of designers who can share new operators with each other to expand the possibilities of what can be produced. He also hopes to integrate Foundry into the workflow of existing CAD systems.

“The user should be able to iterate on the material composition in a similar manner to how they iterate on the geometry of the part being designed,” Vidimče says. “Integrating physics simulations to predict the behavior of the part will allow rapid iteration on the final design.”

www.mit.edu