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Towards Sustainable ‘Biofriendly’ Materials for Additive Manufacturing (Part 1 of 3)

Flickr: Violet Branched Coral Fungus, Author: Jason Hollinger

Image (cropped here) courtesy of Jason Hollinger (CC BY 2.0)
By Michael Floyd and Susan Gladwin

As the additive manufacturing industry grows and extends its reach, it becomes important to ask a number of related health, safety, and environmental questions. While the answers to some of these questions are currently unclear, we have only to look at the natural world to realize that additive manufacturing can indeed be sustainable for humans and the environment. Nature already assembles everything using incredibly sustainable biofriendly processes. The highly complex results are made from 100% renewable resources, and (the Law of the Jungle notwithstanding) are typically non-hazardous to other living organisms.

How do we learn from all this? Biomimicry, which borrows ideas from nature to inform technological development, is one promising approach. Learning from the patterns and strategies found in nature—which have taken eons to evolve—can help guide the way to sustainable innovation. The biosphere abounds with materials worthy of emulation. Consider the beak of the Humboldt squid. Hard, stiff, and tough, it is harder to deform than virtually all known metals and polymers, yet it is made entirely of organic tissue. It’s the hardest non-mineral material found in nature yet this same sharp appendage smoothly transitions through a gradient to the soft jelly-like body of the animal. All because of how it is made.

In pursuit of more sustainable additive manufacturing and a better 3D printing user experience, Autodesk is supporting researchers in the Fall 2015 Greener Solutions class at the University of California Berkeley Center for Green Chemistry (UCBCGC). According to the US EPA, Green Chemistry is “...the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances.”[1] The researchers have been tasked to use biomimicry as a lens for sustainable materials innovation through green chemistry. Armed with 11 design strategies borrowed from the natural world, the class is exploring ways to address and transcend the limitations of existing stereolithography (SLA) resins for 3D printers. Their ultimate goal is to identify promising avenues for the development of high performance materials that are safe for people and for the environment. “The guiding question we had was: how does nature pattern phase change?” says researcher Ann Dennis, an Architecture, Building Science and Sustainability master’s student. “What is the key framework for what SLA printing does? It takes a liquid and turns it to solid in a pattern that you designate.”

The interdisciplinary team of graduate and doctoral researchers is highly motivated to find better alternatives, each bringing different perspectives and insights to the work. Their background includes deep scientific research, public health, and environmental science. One of the researchers, Brian Rodriguez, a Master of Public Health student, points out that, “Nobody has been doing the work to come up with new resin materials for SLA. It’s in a very startup phase and there are a myriad of opportunities and different avenues to pursue. I appreciate Autodesk's commitment to coming up with something that's biofriendly and recyclable, something whose long-term lifecycle impacts are taken into consideration. I’d like to see industry go that way, to incorporate all those aspects when considering what resin materials to make.”

His colleague Chen Cheng, a Chemistry PhD student, concurs: “With some material science, it's all about the properties, and there is not a good understanding of what the chemicals are inside, whereas here we start from the chemicals, then think about the properties and process.” Describing how biomimicry and green chemistry can work in tandem, Rodriguez reminds us, “You can't assume that all chemicals made in nature are safe. Biomimicry can really help you think outside the box, drawing from different parts of nature. And then green chemistry can help you hone in on what the potential hazards are—that's how they can collaborate.”

Given additive manufacturing’s accelerating development, improvements in material sustainability can have extensive, lasting effects. Researcher Lee Ann Hill, a Master of Public Health candidate, has her eye on the bigger picture. “When we think about the resin individually, we think about making it safer so that as it's being manufactured, it's safer; as it's being utilized in industry, it's safer; as it's being utilized by consumers, it's safer; and then when it enters the environment at the end of its life, it's safer. We've been thinking about resin in that kind of circular pattern.”

More biofriendly 3D printing materials will open up a multitude of applications and use cases. The range of potential direct print applications for the biomedical and consumer markets is vast, but until we get the chemistry right, designing for these applications will remain theoretical.

Sustainable additive manufacturing is eminently achievable—we just have to figure out how. “The biosphere has provided a very good example of being sustainable. We can definitely tap into those processes and design principles,” says Cheng.

The students’ work springboards off related research currently underway by The Biomimicry Institute to define characteristics of “biofriendly” SLA resins across the 3D printing lifecycle. As a team, they are laying the foundation for our efforts to catalyze sustainable additive manufacturing material innovations and realize the full potential of 3D printing for the future of making a better world.

In the next installment in this series, we share more about the biomimicry design strategies that are informing the UCBCGC research and hear from other members of the research team.

Read Part 2

[1] http://www2.epa.gov/greenchemistry/basics-green-chemistry