By Adam King
Like a proud papa, Kevin Wolf pulled the gleaming white skull from its glass and aluminum casing. He held it up, much like Hamlet does when confronted with Yorick’s remains in the graveyard, eager to show what 14 hours and the latest technology can produce.
Made of plastic, the skull is an exact three-dimensional replication based on a patient’s magnetic resonance image, but it represents a new frontier in how the world considers manufacturing an object. On a 3-D printer, anything that can be drawn using computer-assisted design (CAD) software can be realized.
Mechanical Engineering Professor Blaine Lilly, who oversees Wolf’s 3-D printing lab, talks in excited tones about the possibilities just at Ohio State: Printing high-temperature parts that can be bolted on to engines at OSU’s Center for Automotive Research and sent screaming across Utah’s Salt Flats at 400 miles per hour, the bioengineering research already taking root and the collaborations that have yet to be realized.
To be fair, 3-D printing is nothing new at Ohio State, and the process, known as additive manufacturing because the printer builds layers until an object is formed, has been around for decades. What’s changing — other than entry-level printers becoming more accessible to all because patents are expiring and price points are dropping — is how faculty, staff and students are rethinking how to use the technology as materials for the printer expand well beyond plastic.
Already surgeons have been suturing on prosthetic earlobes and implanting tracheas that were printed using biocompatible plastic. Companies are attempting to build entire houses using only a 3-D printer. And NASA is touting 3-D printing as essential to its mission.
The space organization recently tested a printed rocket engine injector manufactured using powdered metal fused by lasers. And it is currently testing a printer that it plans to use in zero gravity on the International Space Station and deep-space missions, where astronauts would be able to fabricate tools, replacement parts, housing, labs, electronics, infrastructure (such as roads and landing pads) and perhaps additional spacecraft. NASA is even exploring if food, such as pizza, can be printed.
Having 3-D capability is absolutely driving innovation at Ohio State.
Alok Sutradhar, an OSU assistant professor of plastic surgery who is trying to engineer a stronger prosthetic for facial reconstruction patients, could not have tested his construct without a 3-D printer: The only other option would be to do human implants, and he wasn’t ready for that yet. Working in close collaboration with Michael Miller, chair of the Department of Plastic Surgery and a reconstructive plastic surgeon, Sutradhar said the patients they are trying to help have lost bone structure to cancer or blast injuries, and currently surgeons just approximate how a prosthetic should be made to fill in the gaps of bone and skin.
Because of that absence of structural analysis, Sutradhar, a structural engineer by training, thought he could borrow a method from the aerospace industry called topology optimization, which tries to take the least amount of materials to create maximum strength, such as for an airplane wing.
By applying topology optimization to a prosthetic, Sutradhar envisions it would increase its durability, thus increasing patients’ quality of life and potentially reducing the pain associated with such surgeries.
Sutradhar contracted with the mechanical engineering lab to print skull replicas and the prosthetics to fit each. Then he pressure tested the skulls to determine if the prosthetics could handle different force loads, measured in Newtons.
The average biting force for normal chewing is 200 Newtons, but Sutradhar also tested higher, even for the force of a punch. The testing proved successful, and the next step is to get a surgeon on board so the prosthetic can be implanted in a patient, which could happen as early as next year, Sutradhar said. He is seeking National Institutes of Health funding for the next stages and has built a team that includes Miller and Professor David Dean, a medical 3-D printing expert who joined OSU this month from Case Western Reserve University.
“The next thing I’d like to do is 3-D printing of bone,” Sutradhar said. “You take a calcium-based hydroxy appetite and you can implant it directly in the bone. It’s still in the early phases. There is one group at Washington State that has good ideas. But with our expertise we can try to do something like that here, patient-specific bone generation. If you can create your own bone, your body would be the bioreactor.”
The skulls were made on the older Dimension 3-D printer in the mechanical engineering lab, which can only handle ABS plastic. But a newly acquired printer, a Stratasys Fortus, is top of the line and can print at a higher definition, down to 1/5,000th of an inch (the thickness of a piece of paper) and in eight different polymers, though currently it only has the extrusion heads for four of the polymers (ABS, polycarbonate, ABS-polycarbonate mix, translucent ABS and ALLTEM thermoplastic). Lilly hopes researchers in the Wexner Medical Center will eventually support purchasing a $15,000 biomedical polymer head for the Fortus to build implantable parts.
Both the Fortus and Dimension machines have a constant workflow. Graduate students are using the Fortus to investigate how porous the materials are. For example, if they were to print an enclosed chamber, would it hold gas under pressure? Another student is looking at the tensile strength of a Fortus-printed part as compared to an injection-molded part of the same polymer built using traditional manufacturing methods.
In addition, all mechanical engineering students will get to use the printer in their senior-level manufacturing course as well as their capstone projects. Lilly also teaches product design engineering to about 120 students each semester, and he expects them to utilize the printer as well.
“We’ve really emphasized hands-on learning in our new semester curriculum,” Lilly said. “And we really want our students to know this technology because it is the future.”
Lowell Toms, Stuart Brand and Neil Gardner had the same idea when the lab supervisors in the First Year Engineering program purchased 12 new Makerbot Replicator 2 printers for the Engineering Education Innovation Center on the second and third floors of Hitchock Hall. They want to give students a ground-floor experience with 3-D printing using Solidworks, the modeling software taught in the lab. Students can now print what they model and see how to refine their work.
The Replicator 2 is a $2,200 desktop 3-D printer and can build objects 11.2 inches long x 6 inches wide x 6.1 inches high. By comparison, the Fortus, which has a price tag in the hundreds of thousands, prints at 16 x 14 x 16. Makerbot also uses a polyactic acid filament, which is biodegradable, has less fumes and uses 32 percent less energy than printing with ABS plastic.
Toms said, in addition to supporting the Solidworks curriculum, First Year Engineering hopes to provide printing support for both the honors robotics class and for the Advanced Energy Vehicle project.
“The technical steps to use a 3-D printer are a little above the average citizen,” Toms said. “It’s still going to be a geeky thing for some time. There is a push to set up laser scanners that can scan in three dimensions and then you can hit the print button, but that’s a little ways down the road. Right now these printers are great for an engineering introductory course.”
Benefits for commercialization
The printers are excellent, too, for when a great idea takes its journey into the marketplace.
Subinoy Das, a sinus surgeon at the Wexner Medical Center and director of Ohio State’s Sinus and Allergy Center, wanted to develop a test that doctors could use to determine if a patient’s sinus infection is viral or bacterial. A viral infection, Das said, does not require antibiotics 85 percent of the time, but doctors practice defensive medicine and prescribe them anyway. That opens up the possibility of creating an antibiotic-resistant form of bacteria, especially when 260 million courses of antibiotics are prescribed just in the United States annually.
“If we had a test that could tell what the patient had, both the patient and physician would be more comfortable not taking the antibiotics and they could be placed on better therapies to treat the bacterial infection,” Das said, which he added could revolutionize how health care is practiced.
Das conceptualized a sheathed swab that would travel through the nose cavity and extend once it was deep enough, thereby bypassing the non-harmful bacteria at the front of the nose that could create a false reading and collecting only the bacteria causing the sinus infection. Eventually it could be a self-administered test that a patient could take to a minute clinic or nurse practitioner for results, freeing up physicians and reducing the overall cost of healthcare expenditures.
“The most inefficient use of health care delivery is the problem of not being able to determine if someone has a viral or bacterial infection,” Das said.
Das worked with Paul Reeder and Erika Braun of the Ideation Lab at Ohio State’s Technology Commercialization and Knowledge Transfer Office to develop the prototype. A week after he brought in his specs, Reeder had a 3-D printed version for him to see.
“I thought it was still too rudimentary for what I needed,” Das said. “It didn’t have moveable parts and the initial dimensions of my drawing were off. But I was impressed I could have a prototype a week after working on some drawings with Paul and Erika.”
Reeder contacted Lilly to create a moveable prototype in the Fortus. When an object is created, the printer heats the source material to near melting, so a corn starch-based support material is needed to keep it from drooping. When the printing is complete, the object is dipped into a lye and water bath that dissolves the starch. Because of that support material, the printer can create moveable and removable parts, and with the Fortus it can be done to a level of precision never seen before.
The swab prototype was exactly what Das envisioned.
“Without the 3-D printing, it would have added several months and several thousands to tens of thousands of dollars in costs and development to the project,” Das said. “And it tremendously enhances our ability to generate venture capital money because we have a physical prototype that can capture the imagination of the investor.”
A 3-D printer in the Knowlton School of Architecture is called a ZCOR, and it is unlike the other additive-manufacturing printers on campus. This printer uses powder to create objects, taking a Hewlett Packard print cartridge from which the black ink has been purged and sends a propriety binder through to hold the powder together. “This is essentially really expensive plaster. You excavate the part and literally blow off powder for the finished product,” said Michael Baumberger, the school’s shop and digital fabrication coordinator, who, at left, is holding up a piece he created in the printer. “For our purposes we’re more interested in scale models, so we’re less interested in the property of the material. And that’s the biggest drawback to this is how fragile it is.”
The printed object can be dipped in super glue to give it strength, but that tends to discolor it, Baumberger said. Using powder, though, allows for a super-refined finished product. The ZCOR takes a little more care to maintain than the Stratasys Dimension and Fortus 3-D printers, but it has a faster build time and is less expensive to use.
3-D printing for everyone
The 3-D printing operation in Scott Laboratory is open for Ohio State business, said Professor Blaine Lilly, who oversees the lab.
For a small setup fee and the cost of materials, any faculty, staff or student who wants to use the Department of Mechanical Engineering’s printers can.
The $25 setup fee is smaller than anything charged in the private sector, and the Stratasys Fortus printer is a state-of-the-art model that can currently print in four different materials, including thermoplastic for high-temperature applications.
“It will cost a few hundred dollars if the part is any size at all, but you can do things with this that you can’t do any other way,” Lilly said.
The printer was purchased in part with funds from the OSU-Honda Partnership endowment, with the stipulation that it would be available for the entire university community.
The remainder of the funding came from alumni donations to the Mechanical and Aerospace Engineering curriculum fund, which was created to support the hands-on training of the department’s new semester-based curriculum.
“I imagine once word of this gets out, people will be knocking on our door,” Lilly said.
Ideation Lab prints new ideas
Since it opened in June 2012, the Technology Commercialization Office’s Ideation Lab has designed 37 new products, and No. 38 could be anywhere among Ohio State’s faculty, staff and students. The Ideation Lab’s goal is to bring good ideas to life and determine their greatest potential to maximize their value.
That’s where Ohio State’s 3-D printers come in. They are a critical a final step in the creative process, when the lab fabricates tangible prototypes so inventors can take their product idea off paper and eventually into production.
First, inventors and entrepreneurs work with the lab’s design and prototyping experts through a series of idea generation sessions to develop commercial applications for their ideas. The lab also empowers them to identify and discover innovative trends to conceptualize how their raw ideas fit into the commercial marketplace.
“This is such a valuable resource that most folks don’t know about,” said Paul Reeder, director of the Ideation Lab. “And anyone can have the next million-dollar idea. Sometimes we have to enhance and mature an idea into a viable product. But we can direct people to those collaborations as well. Not every idea requires a patent.”
About 365 ideas came through the Ideation Lab doors in the past fiscal year.
To learn more about the lab, the ideation process or the sessions offered by the lab experts, contact Reeder at 688-1037 or firstname.lastname@example.org, or visit the lab at 1524 N. High St. in the Technology Commercialization Office at the corner of 9th and High.