Engineering co-op student helps federal experts solve a messy high-tech听printing problem
Tomographic 3D printing is a revolutionary technology that uses light to create three-dimensional objects. A projector beams light at a rotating vial containing photocurable resin, and within seconds the desired shape forms inside the vial. The light projections needed to solidify specific 3D regions of the polymer are calculated using tomographic imaging concepts.
The technology was first demonstrated by researchers at the University of California, Berkeley and Lawrence Livermore National Labs in 2019, and a Swiss group at 脡cole Polytechnique F茅d茅rale de Lausanne (EPFL) in 2020. It is significantly faster than traditional 3D printing in layers, can print around existing objects, and does not require support structures.
Though incredible, the technology can get messy in the lab. The vial鈥檚 round shape makes it refract rays like a lens. To counter this, experts use a rectangular index-matching bath that provides a flat surface for rays to pass through correctly. The vial of resin must be dipped in and out of the bath for each use 鈥� creating a slimy situation.
It was slimy, that is, until a student from the University of 蓝莓视频 joined the National Research Council of Canada (NRC) for a virtual co-op term in 2020. Kayley Ting, who is doing a bachelor of applied science (BASc) degree in biomedical engineering, worked with machine vision and 3D printing experts from the NRC鈥檚 Digital Technologies and Security and Disruptive Technologies Research Centres.
Together they developed a technology that computationally corrects for optical distortions. New equations compensate for the vial鈥檚 round shape and eliminate the need for the goopy, square bath, while still enabling the nearly instant production of precise polymer shapes using light.
Now you see it, now you don鈥檛: tomographic printing using the goopy index bath (above) and freed from bath (below). The green light in the vial is fluorescence 鈥� a by-product of the 3D printing process that conveniently highlights the path of light in the vial.
The team also developed new code to program the printer so that it could produce complex objects and be easily used by non-experts. They recently in Optics Express, an open-access scientific journal, and revealed a few dazzling shapes they produced.
Due to COVID-19 pandemic restrictions, Kayley could not access the lab in Ottawa where objects are printed. But that didn鈥檛 stop her from innovating at a distance. To print complex objects using STL files, Kayley wrote the code that imports the 3D object file, slices it, and converts 2D slices to the light projections that will be shone听on the vial. Intensive computations are required at this step.
鈥淲hile it used to take about an hour to process a print file, Kayley鈥檚 version of the code usually takes less than a minute to execute,鈥� says Antony Orth, research officer from Digital Technologies and Kayley鈥檚 supervisor.
The progress made by Kayley during her virtual work term at the NRC will have practical applications in the future.
鈥淜ayley also produced a simple user interface with buttons and menus that enables people to use the printer without knowing how to code. This is a huge deal for us as it will make the technology much more usable at the NRC and for others interested in tomographic 3D printing,鈥� says Chantal Paquet, research officer from Security and Disruptive Technologies.
Each year, the NRC welcomes over 300 co-op students to work alongside leading experts. Students bring fresh ideas and tremendous energy for project execution, helping NRC experts advance cutting鈥慹dge research, while NRC experts provide coaching, advice, experience, mentorship, direction, and (in non-pandemic times) access to research infrastructure in industrial settings, helping students reach their scientific and professional goals more rapidly and in a supportive environment.
鈥淒uring my co-op term, I was able to apply concepts from physics, math and computer science, and felt I could have a tangible impact on a project with a variety of real-world applications,鈥� Kayley says. 鈥淚'm so grateful to have had this opportunity, and to receive mentorship from accomplished researchers at the NRC.鈥�
Kayley plans to complete her bachelor's degree in biomedical engineering in 2023, and hopes to pursue graduate studies in simulation engineering or medical robotics.
"This is a terrific example of how our students and employers like the NRC both benefit from our co-op program," says Mary Wells, the dean of 蓝莓视频 Engineering. "I'm proud of the contributions talented students like Kayley make as they work towards their degrees in the real world as well as the classroom."
