Mihaela Vlasea might have headed off to medical school after earning her Bachelor of Applied Science in mechatronics engineering degree at the University of Waterloo.
Instead, she chose to stay to push three-dimensional (3D) printing into new territory: Bone replacements that have the porosity and function of the real thing.
For thousands of Canadians facing surgery to deal with the pain of faulty joints, this holds the possibility of improved, lasting remedies.
“I could see where my technique would have an impact right away,’’ Vlasea says.
Researchers prefer the term “additive manufacturing” to describe any one of several processes that produce three-dimensional objects by fusing together material one tiny layer or strand at a time. Heat and organic or inorganic binders can all play a role in the process.
Focused light, often in the form of lasers, offers one source. Vlasea’s work involves ultraviolet light, an inorganic binder, and a compound called calcium polyphosphate.
Although it has been around for almost 27 years, additive manufacturing has only recently — over the last five years — drawn wide, wonderstruck attention in and out of the academic community.
Machines have become smaller, smarter and cheaper. The materials they currently use range across different types of metals, plastics and ceramics.
Researchers have stopped wondering whether they will ever make organs and other body parts using live cells as media.
Now, they ask, how well can they do it? Functional organs are just around the corner.
Although 3D printers differ in method, they have at least one thing in common: They like to read. Nothing gets done without somebody creating a computer-aided design (CAD) file that lays out the dimensions and features of the product.
“We’re getting some fantastic physical properties out of additive manufacturing,” says Ehsan Toyserkani, who runs Waterloo’s Multi-Scale Additive Manufacturing Laboratory (MSAM) located in Engineering 3. “The mechanical strength we are getting is much better — in some cases as much as 25 per cent improvement — over conventional manufacturing.”
Toyserkani’s lab, where Vlasea does much of her research, spins off patentable developments in additive manufacturing. By exploring “micro-scale additive manufacturing,” it has found a way to embed sensors into metallic objects as they are being printed.
Waterloo researchers also developed a means of monitoring and sensing the process zone in laser direct metal fabrication, one form of 3D printing, to improve its repeatability, accuracy and reliability.
“At the moment, we have been recognized as the first university in Canada doing extensive research and development in additive manufacturing. Waterloo hopes to enable the next generation of additive manufacturing processes and advance the existing technologies for numerous applications through a holistic approach."EHSAN TOYSERKANI
"Several universities, coast-to-coast, have recently started working on this area, so we expect to see multiple national collaborative projects,” says Toyserkani, an associate professor in the Department of Mechanical and Mechatronics Engineering in the Faculty of Engineering.
PLASTIC PROTOTYPING: MANIFOLD DESTINY
Across Waterloo’s campuses, additive manufacturing has moved from the fringes of learning to the mainstream.
Toyserkani’s research team works with five machines it built from scratch or bought and modified. His team experiments with materials and methods in the emerging field of bioengineering. Vlasea’s work since 2008 has earned her a BASc and a PhD in mechatronics engineering. She’s now doing post-doctoral research in the Faculty of Engineering.
Elsewhere on campus, a group of students last year used laser sintering, a form of 3D printing, to fuse chocolate into three-dimensional objects.
But most of the additive manufacturing happening at Waterloo turns out parts and prototypes made of plastic.
Quick and inexpensive, a 3D-printing process known as fused deposition modelling offers students and faculty a means of rapidly giving shape to ideas rattling around in their heads.
“We’re able to design something in the evening and try it the next day,” says Thomas Abdallah, a second-year mechanical engineering student on the University of Waterloo Alternative Fuels Team. “Now we’re at the point where we can print iterations and have them work really well.”
The team printed an air-intake manifold to squeeze into the snug engine compartment of its modified car.
Fused deposition modelling lays down filaments of heated plastic. Objects take shape over several hours or days, depending on complexity.
Still, it’s faster and cheaper than having a machine shop make a prototype in metal. Additive manufacturing takes some of the risk out of prototyping.
Men and women living in the Velocity Residence for student entrepreneurs don’t have to travel far to work out an idea in three dimensions. They can build prototypes on an in-house MakerBot printer, which uses fused deposition modelling. MakerBots are small enough for home use.
At the School of Architecture, in Cambridge, students have access to a MakerBot and a larger fused deposition printer.
“They’ll use 3D printing to solve design issues,” says Heinz Koller, manager of the school’s fabrication laboratory. “It’s often more effective to hand somebody a 3D model, as opposed to trying to explain a 2D sketch.”
One event more than any other widened the eyes of the Waterloo community to the potential of additive manufacturing.
In February 2013, the Sedra Student Design Centre in Engineering 5 formally opened its 3D Print Centre to introduce its star tenant — a Fortus 360mc printer.
A display case at the centre contains chess pieces, an IronMan mask and tools with moving parts — made of plastic by fused deposition in the Fortus. Available to all Waterloo students and faculty, the printer often runs around the clock to meet demand.
Additive manufacturing helps drive inventiveness, says Peter Teertstra, director of the Student Design Centre.
“It affects the way you design,” he says. “On paper, you can never completely visualize all the parts to see how they fit.”
Now students can spot flaws in function and quickly try again, he says.
Printed plastic parts are often strong enough to replace machined-metal components. A.J. Rosewarne, president of Waterloo’s robotics team, says printing shaved off a month’s work as the team heads to competition this spring.
Competition teams and engineering students putting together fourth-year projects aren’t the only users of the Fortus. Teertstra says he’s impressed by the level of innovation and entrepreneurship students in other programs show when they come to the print centre.
Clients usually meet with Genie Kim. A first-year mechatronics student, Kim helps students refine their CAD files and choose their plastics. The print centre is her co-op placement.
“It’s that trial-and-error part, and that interaction with customers, that makes this job a lot of fun,” Kim says.
Besides turning out parts and prototypes for projects, students book time on the printer for incidental items.
One student learned enough about CAD files to print a replacement plug for a cellphone charger. Others made hearts for Valentine’s Day.
The Fortus arrived in the print centre thanks to a Waterloo partnership with two leaders in the 3D-printing business, Cimetrix Solutions and Stratasys Ltd. The print centre installed the unit for $100,000 — the amount it received as a grant from the DENSO North America Foundation.
It also has a relationship the Hyphen division of Christie Digital Systems Canada Inc., a company based in Kitchener. Students get reduced-cost access to Hyphen’s expertise and equipment in additive manufacturing.
“Anything they can’t do, we can probably do for them,” says Mark Barfoot, Hyphen’s managing director. Barfoot is a Waterloo mechanical engineering graduate (’98).
HOW IS WATERLOO USING 3D PRINTING?
For research and development
Porosity is a golden word in the Multi-Scale Additive Manufacturing Laboratory. Researchers use additive manufacturing to develop such things as gone and dental implants that closely match the real ones in form and function.
For parts and prototyping
A large 3D printer in Engineering 5 often runs around the clock, turning ideas that students and faculty have dreamed up into tangible plastic objects. Besides prototypes, output from the centre includes working parts that might end up in a robot rover or alternative-fuels vehicle.
To teach design
Additive manufacturing helps students at Waterloo’s School of Architecture, in Cambridge, experiment with shape. Shapes that don’t appear to work on paper sometimes do when they’re printed in 3D. Students can also test their ideas by printing plastic models of buildings and streetscapes.
To solve problems
Voltera Inc., a startup based in Waterloo’s Velocity Garage, uses conductive ink to make inexpensive, rigid circuit boards — without the toxicity of conventional, chemical-based processes. Device-makers can try different iterations of a circuit board without going broke. Although not 3D printing in the usual sense, it is rapid prototyping, and it is meant to be a desktop tool.
BETTER JOINTS, ONE STEP AT A TIME
Ehsan Toyserkani keeps a collection of items to demonstrate what additive manufacturing can do. The collection includes a manufactured vertebra and a tooth, and a small graceful sail made of metal — all printed by machines in the MSAM lab down the hall from his office.
Doctoral candidate Ahmad Basalah works with titanium to 3D print porous scaffolds for rebuilding tissue.
“My ultimate goal is to build a whole porous knee replacement,” he says.
A better dental implant might be the outcome of the research Farid Behzadian, a master’s student, does at the lab.
Recently graduated and exploring her options in 2008, Vlasea took up an invitation from Toyserkani to check into a project run by the University of Toronto and Mount Sinai Hospital. The University of Guelph, McMaster University and Queen’s University in Kingston are also partners.
Vlasea used her background in engineering to build a 3D printer that makes skeletal parts with remarkable bone-like features, from a porous surface to nutrient-carrying tubes and channels inside.
Using ultraviolet light and a binding agent, the process fuses powdered calcium polyphosphate into a biodegradable scaffold with intricate internal porous features. The aim is to have bone cells migrate into the implanted scaffold, the way coral forms on a shipwreck.
As the cells replace the compound, a natural, better-fitting part takes shape. So far, testing has been limited to animals.
Researchers also want cartilage cells to latch onto the surface, creating a more compatible interface between the manufactured joint and the natural bone and cartilage that surrounds it.
Conventional joint replacements using plastics, metals and ceramics relieve pain and restore mobility, but they don’t work forever. Hip replacements typically last 10-15 years, according to the Canadian Joint Replacement Registry.
Each tweak of her process, each new part the printer turns out, moves Vlasea closer to scaffolds that more precisely mimic natural bone.
“I am very happy about how things turned out because of three reasons. I got to work with an amazing interdisciplinary group. I am now involved in the additive manufacturing wave that is sweeping technology across a multitude of sectors. I got to use my engineering skills to build a 3D-printing machine. How cool is that?”MIHAELA VLASEA
WHERE IS 3D PRINTING TAKING US?
Three-dimensional printers are now small enough to sit on a desk, but does that mean everybody will want one?
Mark Barfoot has his doubts. The managing director of Hyphen, a Kitchener-based service that offers businesses— and University of Waterloo students — its expertise in 3D printing, Barfoot sees another scenario: The neighbourhood print shop.
“That’s more the model that I would see, where someone would go to a service place,” he says. “They bring in their part and somebody either scans it, or models it for them, and prints it.”
But, he says, there is no question 3D printing — additive manufacturing as it also known — creates opportunities while it changes the way things are developed and manufactured.
Not that long ago, the talk about 3D printing focused on what it could do for rapid prototyping, Barfoot says. Now, with the wide range of materials it can use — and the precision it delivers — additive manufacturing is seen as the answer to low-run production needs.
Ehsan Toyserkani, the University of Waterloo professor in charge of the Multi-Scale Additive Manufacturing Laboratory in Engineering 5, sees additive manufacturing as complementing conventional mass production or filling niches that mass production misses.
Additive manufacturing enjoys advantages, he says, in its ability to cut the cost of prototyping, make complex objects that can’t be stamped or cast, and reduce energy waste.
In “Disruptive manufacturing: The effects of 3D printing,” Deloitte LLP consultant Benjamin Grynol writes “3D printing will potentially have a greater impact on the world over the next 20 years than all of the innovations from the Industrial Revolution combined.”
Industries that overlook additive manufacturing, Grynol contends, will face competition not only from more-adaptive companies but from inventive consumers using the technology at home or elsewhere. New business opportunities will surface as 3D printing becomes more accessible, he adds.
“To fully capitalize on these opportunities, governments may choose to make 3D printing widely accessible within free public service locations, such as schools and libraries,” Grynol writes in his report.