A recipe for sustainable 3D printing

Preparing a new recipe from a cookbook usually means a trip to the grocery store for fresh ingredients, but a new recipe book created by a postdoctoral fellow at The University of New Mexico School of Engineering calls for used eggshells over eggs.

Fiona Bell, a postdoctoral fellow in the Department of Computer Science Hand and Machine Lab, recently created a sustainable recipe book for common, at-home 3D printers titled “Biomaterial Recipes for 3D Printing: A Cookbook of Sustainable and Extrudable Bio-Pastes.” The book includes recipes made from orange peels, sawdust, and tree leaves. It also teaches readers how to get creative with the materials available to them and test their own recipes.

Much of the existing work in 3D printing is related to plastic. While the technology offers a lot of potential for different forms of manufacturing, Bell and other researchers in the Hand and Machine Lab are interested in exploring the use of more sustainable alternatives, especially when it comes to developing recipes and software that can be used on the small-scale 3D printers consumers have access to.

“While the recipes provide a sustainable alternative to plastics, the entire cookbook in and of itself is a powerful artifact because it allows people to engage with these sustainable materials that might seem high-tech or unattainable in a very natural and accessible way,” Bell said.

While testing recipes for the book, Bell sourced a number of items from local waste streams, including cottonwood leaves from the UNM campus, sawdust from a local furniture artist’s woodshop, and waste eggshells from Frontier Restaurant. In the recipes, these items act as fillers, or the ingredients that make up most of the printing material.

The book also walks readers through the need for stabilizers, non-absorbent materials that provide stability to the object as it is printed, like sand or eggshells; binders, absorbent ingredients that help keep materials together, like wheat flour or gelatin; and liquids, which help turn the materials into a paste, like water.

After objects are printed, they can be made waterproof with beeswax or shiny with vegetable oil. During recipe development, the lab printed a number of different objects with the paste, like compostable plant pots, birdhouses, vases and more. Each recipe in the book includes details on the amount of time it takes for the objects to decompose in soil, ranging from 60 to 90 days. Bell also documented recipe failures, like what printed objects looked like without binders or stabilizers and an orange peel design that began to grow mold.

“Most 3D printing focuses on plastics, whereas all of these are made from different bio-waste streams that exist in our local community,” she said. “We’ve been able to look at our local communities and think about what materials are produced, what goes to waste and how we can reuse those wastes and give them second lives before returning them to the earth.”

In March, Bell received the Best Pictorial Award at the ACM TEI Conference on Tangible, Embedded and Embodied Interaction in Bordeaux, France, alongside Camila Friedman-Gerlicz and Leah Buechley for the recipe book.

Bell has brought a diverse skill set to the lab with a Ph.D. in Creative Technology and Design from the ATLAS Institute at the University of Colorado Boulder and a Bachelor of Science in Mechanical Engineering from Santa Clara University.