The 3rd Dimension

BTI Researchers test 3-D printing technology to scale up—and down

Since it first appeared on the market in 1984, 3-D printing technology, also known as stereolithography, has been used to create everything from robotic aircraft to artificial limbs. The technology caught the attention of the media this summer, when reports surfaced that a Canadian man fired 14 shots from a rifle manufactured on a 3-D printer using a design downloaded from the Internet.

The cost of the technology is becoming more affordable—desktop units now range from $250-$2500—and the printers are finding their way into artist studios, research labs, and in some cities, the local Fedex/Kinkos copy shop.

In 2012, BTI members Brett Barney (BTI/Department of Bioproducts and Biosystems Engineering) and Igor Libourel (BTI/Department of Plant Biology) approached BTI director Mike Sadowsky for funds to purchase a MakerBot Replicator 2—a low-cost 3-D printer about the size of bread box. Both saw the potential to advance research and training goals but each had a novel approach to experimenting with the technology.

Barney immediately saw the potential of the technology in the classroom and has created brightly colored, hand-painted models to help explain cell metabolism and metabolic pathways to his students.

Beginning with three dimensional images of proteins from the Protein Data Bank, a repository of structural images for large biological molecules, he uses a variety of

3-D rendering tools to refine his models and build the scaffolding required to support the structure as the printer lays down layer upon layer of ASB thermoplastic, similar that found in Lego® building blocks. After cutting away the scaffolding and the excess material, the molecular models are painted, polished and ready for display.

The initial models took up to 15 hours to print, with several additional hours of detailed work for clean up and finish. With practice, he was able to reduce the printing and clean up cycle to a couple of hours. Once the models are complete, Barney posts the plans, with photographs and annotations, on Makerbot’s open-source repository called Thingiverse. Published under the name MoleculeMaker, Barney’s model of the FeMo Cofactor is available for download by members of the online community.

Barney hopes to print a full model of a photosynthetic reaction center, but also builds partial models to highlight unique characteristics of the molecules he studies. In fact, his lab has used the models to help predict sites for mutagenesis studies in wax ester synthases—enzymes important in the effort to produce biodiesel from a complex biomass such as cellulose. Barney recently published the
results in the Journal of Applied and Environmental Microbiology.

For more about Barney’s 3-D Models see: http://barneybioproductslab.cfans.umn.edu/3d-printing-and-molecular-models/ 


Rapid prototyping and development of miniature bioflow reactors

With an eye toward understanding environmental changes brought about by global warming, the Libourel Lab studies metabolic features of Ostreococcus, a picoalgae genus common in the world’s ocean. Investigating the relationship between metabolic adaptation and climate models, the lab relies on bioflow reactors to manipulate and monitor the organism’s response to evolutionary pressure.

After modifying bench scale reactors with customized hardware and software, Libourel and his students realized they could achieve the same results, using fewer resources, by scaling down. But each bioreactor requires a custom enclosure, which can cost as much as $500 to produce, increasing cost and slowing development. Using the Replicator 3-D printer, Libourel hopes to construct and modify the enclosures which house the circuits, pumps, and fans required to run the reactors. In addition to the cost saving, the rapid prototyping and development will allow the lab focus on what’s happening inside the dish instead of the box.