Multi-Material 3D printing and Stratasys: let’s talk about what that is, what’s the advantage, what’s the appeal, and what’s the feasibility of using that in Design going forward?

What is multi-material printing? It is the idea that you can print multiple materials within the same component. Some recent examples of this method may have been presented as a small plastic nub printed simultaneously with a small figurine inside. While that specific example leans heavily on aesthetics, this introduces a whole new field of applications for engineering.

Imagine you wanted to have the stiffness of a component vary over its length. You could have the core of that component be one material that is stiff and vary its width over the length of the component. Then you could encase that in a less stiff material. The stiffness of the component would vary over its length. This is where it starts to get interesting. On many occasions, engineers have to use homogenous materials, but instead of varying geometry (which is what they have to do today with homogenous materials), what if you varied the stiffness of the material instead? The geometry would stay the same, even when you 3D printed it. You can solve a whole new set of design problems with this idea.

How feasible is this idea? To start, engineers today have not been trained to use different materials interwoven in one model. Most experience and design to date has been based on homogenous materials. To vary a model in the material but not in the geometry requires a very different mindset. Second, new tools would have to be developed in order to design a model with multiple materials.  How do you design with two discreetly different materials? As you progress through the design, you move into materials with properties that can vary continuously, instead of discreetly (ie. discreet boundary). There are no tools today that let you specify this, not even within a CAD tool or even within an STL (which you’ll be sending off to a 3D printer), or more advanced, more accurate representations.

One of the great benefits of generative design and 3D printing is that it frees engineers up from constraints previously set by subtractive manufacturing to let them solve design problems in more creative ways. Multi-material 3D printing provides a whole new set of opportunities. Today, it doesn’t appear that the tools are quite ready to enable it. We know of 3D printers that are in development to allow for multi-material printing and that Stratasys have been working to allow for similar options. However, we are not yet at the point of enabling engineers to work with this printing method, though all signs point to the release of a prototype in the near future. That’s it. Take care, talk soon.