3D printing has progressed over the past decade to include multimaterial fabrication, enabling production of powerful, functional objects. While many advances have been made, it still has been difficult for non-programmers to create objects made of many materials (or mixtures of materials) without a more user-friendly interface.

A ping-pong paddle fabricated with Foundry software. (Photo: Kiril Vidimče/MIT CSAIL)

A team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) developed a system for custom-designing a variety of 3D printed objects with multiple materials. With existing multi-material 3D printers, parts are designed in a traditional CAD system and a print software allows users to assign a single material to each part. The new system, called Foundry, lets users vary material properties at a very fine resolution that has not been achievable previously. The team designed and fabricated a ping-pong paddle, skis with retro-reflective surfaces, a tricycle wheel, a helmet, and a bone that could someday be used for surgical planning.

Redesigning multi-material objects in existing design tools would take experienced engineers many days, and some designs would actually be completely infeasible. With Foundry, the designs can be created in minutes.

To use Foundry, an object is designed in a CAD package, and when the file is exported, the user can determine the object’s composition by creating an “operator graph” that may include any of approximately 100 actions called “operators.” These operators can subdivide, remap, or assign materials; some divide an object into two or more different materials, and some provide a gradual shift from one material to another.

Foundry lets users mix and match any combination of materials, and also assign specific properties to different parts of the object, combining operators together to make new ones. If a part needs to be both rigid and elastic, a rigid operator and an elastomer operator both would be assigned; a third “gradient operator” connects the two and introduces a gradual transition between materials.

Using Foundry to exploit the full capabilities of a 3D printing platform enables practical applications in medicine and other industries. For example, surgeons could create replicas of objects like bones to practice on, and doctors could develop more comfortable dentures and other products that would benefit from having both soft and rigid components.

Watch a video of the software in use on Tech Briefs TV at www.techbriefs.com/tv/Foundry.