Specifically, Autodesk is backing work from students at the UC Berkeley Center for Green Chemistry who are focusing on developing materials to replace stereolithography (SLA) resins, which are known toxins and have already proven deadly to aquatic life, the organizations said. To do this, researchers are borrowing from examples of organic materials found in the natural aquatic world to come up with materials that also are bio-friendly and recyclable, a design process called biomimicry.
“We wanted to better understand what it would mean for the materials used in 3D printing to be “greener,” said Dawn Danby, senior sustainable design program manager at Autodesk. “We asked, very simply: What are the environmental or safety challenges, and where are there opportunities to improve things? Some processes for additive manufacturing, like DLP as used in our Ember 3D printer, depend on chemical reactions. Naturally, we reached out to the experts in Green Chemistry at UC Berkeley, along with their collaborators at the Biomimicry Institute, to do a deep dive into the opportunities in SLA resins.”
The SLA additive manufacturing process creates models, prototypes, and production parts layer by layer using a process called photopolymerization, in which light causes chains of molecules to link together to form polymers.
The Ember 3D printer from Autodesk.
Danby said that SLA 3D printing is the target for the product because it’s the process used in Autodesk’s Ember printer and is particularly ripe for materials innovation, since there’s been relatively little work done to develop new materials for the market.
“Safer, more sustainable materials could mean expanding the uses for printed products, particularly if those materials are coming into contact with people or the environment,” she said.
The existing liquid resins used in SLA 3D printing are chemically derived from petroleum, a non-renewable resource, and require cautious handling, according to a blog post on the Autodesk website about the partnership. In fact, a study published last November out of UC Riverside found that parts produced by this, as well as other 3D-printed processes, were toxic to fish embryos, leading researchers to seek alternative materials.
While they may not be eco-friendly, current SLA materials do have the benefit of being highly reactive, allowing for tightly controlled chemical reactions that can create high-resolution 3D prints, researchers said in the post. They acknowledged that it will be a challenge to achieve the same quality of resin with more eco-friendly materials not based in petroleum. However, they are already exploring 11 biomimicry-inspired design themes to come up with new materials, said Tom McKeag of the UC Berkeley team, in another blog post on the Autodesk site about the project.
Those themes include “shape is strength,” which provides structural advantage that is the result of millions of years of natural selection found in nature, he wrote.
Often that advantage means the saving of material and energy by using a better shape,” McKeag wrote. “A common example is the bone structure of birds, where lightness and strength are required and stresses are resisted by the geometry of the bone. Moreover, extra material is grown only in those places experiencing greater stress and as a result of that stress.”
CAD files that direct objects made using 3D printers already use this type of design, he said. It’s now being applied by the Berkeley team to other parts of the process, including the development of safer resins.
“It may be possible to initiate voids within the liquid resin itself at a smaller linear scale,” McKeag wrote. “It may also be possible to create new shapes by how the resin is laid up, using a ‘cookie batter’ approach, or tacky pull away method, for example.”
Autodesk will continue to support the work by researchers at the Berkeley center and highlight it on its website as they make further progress with the ultimate goal of sustainable materials innovation, Danby told us. “In additive manufacturing specifically, it would be wonderful to be able to direct our customers to more alternatives in the market, opening up the possibilities for what they can make with additive manufacturing,” she said.
Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 15 years. She has lived and worked as a professional journalist in Phoenix, San Francisco, and New York City. In her free time she enjoys surfing, traveling, music, yoga, and cooking. She currently resides in a village on the southwest coast of Portugal.