Michigan Tech University’s Lab in Open Sustainability Technology has gone the extra mile in making 3D printing technology ultra-sustainable.
My previous post about distributed 3D printing as a foundational technology that can bring the circular economy into reality prompted quite a bit of conversation. There were lots of questions about the feasibility and economics of the idea — so to dig deeper, I reached out to Joshua Pearce, director of Michigan Tech University’s Lab in Open Sustainability Technology.
Motivated by addressing the world’s sustainability challenges, Dr. Pearce’s original research focused on driving down the cost of solar cells. But while developing a solar-powered laptop, he found the cost of producing a custom plastic computer casing prohibitive. A search for cheaper alternatives led to him to open-source 3D printers and, in his words, “It just kind of took over my research.”
His work has since expanded to the sustainability opportunities that 3D printing offers for addressing development challenges in emerging economies, as well as its transformational potential in advanced economies like the United States and Europe. As he says, “In the end, everybody is going to be manufacturing the same way — the least expensive — which happens to be distributed manufacturing with 3D printing.”
Pearce discovered the economics of 3D printing when his lab needed high-end scientific instruments that sold for thousands of dollars from specialty manufacturers. Using an inexpensive 3D printer, his lab was able to fabricate expensive items like syringe pumps for a fraction of their retail cost. “Combining open-source electronics with 3D printing,” says Pearce, “it’s very easy to show economics for high-end products.”
Currently, the economics are still there, but are less overwhelming with simple objects like shower-curtain rings that can be spit off high-volume assembly lines in low-wage countries. Of course, those products are cheap largely because the negative environmental and human externalities associated with production and disposal go unpriced. Still, the financial trend is clear, as printing them yourself still costs less than buying them.
To recover the investment cost of a single open-source 3D printing machine that retails for about $500, you have to print a collection of objects that saves you $500 over the market cost. There are many products for which the printing economics become compelling. Take orthotics — those custom-made foot supports that you insert into shoes. Custom orthotics run between $400 and $600 on average, so printing them at home can cover your printer cost immediately. For anything you print afterwards, you only pay the marginal costs of materials and energy.
“So that’s why I’m very bullish on this,” explains Pearce. “I think people are going to start producing a lot of their own things, whether it’s kids' toys or scientific instruments, purely based on the economics. And the beautiful part of this is, the economics are finally pushing us towards the right environmental solution.”
Part of the environmental dividend comes because 3D printing facilitates the circular economy and the recycling of materials. For plastics, the economics can be eye-popping. Commercial filament used for 3D printing sells for $25 per kilogram on the low-end, and around $50 per kilogram on the high-end. If you buy commercial plastic pellets for producing your own filament, it’s $5 per kilogram. But if you recycle your own prints or use waste plastics, the price goes down to about 10 cents per kilogram! Economics like that are hard to beat, even with the scale economies of giant industrial production plants.
First-generation recycling technology, known as recyclebots, already exist and work by grind up old prints and waste plastic like milk jugs to extrude new filament. The plans for producing them are freely available on the Internet, and some of the parts can even be manufactured using a 3D printer. According to Pearce, “Recyclebot technology is maybe five years behind where the 3D printers are, so making filament is time-consuming and aggravating. But that technology will eventually mature as well.”
While recycling materials is vital to the circular economy, every transformation of materials — say, from obsolete laboratory equipment into new orthotics — requires energy. For 3D printers to be sustainable, they will need to run on renewable energy sources. Since most printers operate on electric power, the question is, can distributed 3D manufacturing run on solar power?
“Absolutely,” is Pearce’s response. “We have already done it. You can put your modules outside and run a wire into your house or your building. That’s actually how we did the all the original testing.” They now have several kinds of solar-powered 3D printers, also all available open source, and have also designed a solar-powered recyclebot that functions with a small solar panel. The unit can be allowed to run while the sun shines and produce “filament all day long,” says Pearce.
While the technology is still developing, it is clear that the foundations of a circular economy built on solar-powered 3D printing know-how are already being set.