While many people may still think that plastic is the only 3D printable material out there, that’s definitely not the case. Obviously there’s metal 3D printing, and biomaterials, flexible filaments and metamaterials. Then you move into wood and food, and even stranger materials, like algae and crushed grape skins. But today, we’re focusing on what is possibly the most unlikely 3D printing material of all – human waste. And no, I don’t mean e-waste or plastic waste.
Fourteen undergraduate students from three departments at the University of Calgary in Canada recently competed at the International Genetically Engineered Machine (iGEM) Foundation’s Giant Jamboree. Almost 5,000 students from 330 universities presented their best ideas on synthetic biology, and the U Calgary team took home the gold with their innovative project, cleverly titled Astroplastic: From Colon to Colony. If you hadn’t guessed by the name, the team has developed a way to use human waste as a major bioplastic ingredient for astronauts 3D printing in space.For the project, the team, which was mentored by six faculty advisers, used the accepted, NASA-sanctioned recipe for simulated human waste, which includes cellulose, miso paste, peanut oil, and yeast – learn something new every day, right?
Alina Kunitskaya, a fourth-year chemical engineering student at the university’s Schulich School of Engineering, said, “We actually tried to pursue the route of using the real thing, but no one wanted to have it inside the lab.”
Kunitskaya, who specializes in biomedical engineering, helped lead the U Calgary team to gold with their theory of converting human waste into useful, 3D printed bioplastic tools during deep-space missions. However gross it may be to think about, it is definitely an abundant source of material that’s unlikely to run out on a potential mission to Mars.
Kunitskaya explained, “With space travel, such as a three-year mission to Mars, there are major challenges to overcome.
“Transporting material is difficult and expensive, and how do you anticipate every challenge and everything you need over three years on a trip to Mars? Recycling waste is another major challenge.
“We got the team together at the beginning of the winter semester and started brainstorming ideas, and each person came up with their own idea.
“The only criteria is having synthetic biology which is engineering bacteria to do something useful. And at first, our idea was to make plastic out of wastewater.”
After the team took a trip to Calgary’s wastewater treatment plant and then brainstormed some more, their idea transformed into a solution for astronauts in deep-space. With some advice from former ISS commander Chris Hadfield, the first Canadian astronaut to walk in space, and the university’s Chancellor Robert Thirsk, the team got to work on its poop-to-plastic concept.
Last week, the U Calgary iGEM team published a paper on their work, titled “Astroplastic: A start-to-finish process for polyhydroxybutyrate production from solid human waste using genetically engineered bacteria to address the challenges for future manned Mars missions,” which is available online.
The team’s project summary reads, “This year, the University of Calgary’s project involves using genetically engineered E. coli to turn human waste into bioplastics.
“We envision our project as a start-to-finish integrated system that can be used in space to generate items useful to astronauts during early Mars missions. This will solve the problem of waste management by upcycling solid human waste into a usable product.”
Co-authors include Xingyu Chen, Syeda Ibrahim, Kunitskaya, Kaitlin Schaaf, Zi Fei Wang, Preetha Gopalakrishan, Maliyat Noor, Harry Wilton-Clark, Jacob Grainger, Alexandra Ivanova, Patricia Lim, Michaela Olsakova, Lalit Bharadwaj, Bilal Sher, David Feehan, Rachelle Varga, and Mayi Arcellana-Panlilio.
Their method actually works, too – the team successfully produced their bioplastic in the Bachelor of Health Sciences laboratory. Genetically engineered Escherichia coli (E. coli) bacteria is used to convert human waste into polyhydroxybutyrate plastic – the waste is left alone for several days, in order for its levels of volatile fatty acids (VFAs) to increase. Then, a centrifugal and filtration process extracts the VFAs from the waste solids, and the substance is moved to a separate fermentation tank, with the E. coli.
An SLS 3D printer can then use the resulting bioplastic to manufacture objects like tools, while leftover solid waste products, according to Digital Trends, could possibly be used to make radiation shields.
The team’s attention to iGEM requirements and detailed research won them a gold medal, in addition to being nominated for the event’s Best Manufacturing Project. But they’re not done yet – two students plan to test their plastic-making process in low gravity this July on Canada’s Falcon 2.0 aircraft. The goal will be to extract nanosized plastic granules from the bacteria, instead of commencing the entire polyhydroxybutyrate extraction and 3D printing process, as microgravity can only be simulated for a few minutes at time.
In addition, the U Calgary iGEM team hopes to learn how to make different kinds of plastic, so they can manufacture items for space applications with different flexibility and strength levels. Now, if you’ll excuse me, I have the sudden urge to wash my hands.
What do you think about this project? Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.[Source/Images: University of Calgary]