Online engineering student uses education to fuel personal business


By Miranda Buckheit

UNIVERSITY PARK, Pa. — By day, Tim Ayres is an employee at Lockheed Martin working on airplanes, fluid systems and hydraulic parts. By evening, Ayres is a 3D printing entrepreneur and a Penn State World Campus graduate student.

When the online master’s degree in additive manufacturing and design was offered in fall 2017, Ayres knew he needed to enroll.

“I remember when I heard about the program and how it was one of the first of its kind in the country,” Ayres said. “It was definitely exciting.”

The novelty of the program appealed to Ayres, who was intrigued by the budding technology in the field of additive manufacturing — especially as he runs his own 3D printing shop in Arlington, Texas. The program could help him improve his business, without having to uproot his life and move to Pennsylvania.

“I’m learning far more about the science of 3D printing materials and a bunch of other topics,” Ayres said. “3D printing is very multidisciplinary; I didn’t have a solid background in some of the things that I am learning, so it’s been exciting to dig deep into the various aspects of additive manufacturing.”

The binder jetting process

Ayres joined with fellow Penn State University Park graduate student Santosh Reddy Sama to investigate novel methods to improve the mechanical and temperature performance of a process called binder jetting, a common practice in additive manufacturing for making 3D pieces. They worked under the mentorship of Sanjay B. Joshi, professor of industrial engineering, and Guha P. Manogharan, assistant professor of mechanical engineering and industrial and manufacturing engineering.

During binder jetting, powder particles like sand, metal or ceramic are spread across a bed to form a layer. The loose powder particles are bound together by a liquid binder, such as water, that is deposited on the powder layer using an inkjet type mechanism.

“After each layer, more powder is spread across the bed, and the process repeats until you’re done,” Ayres said.

The completed 3D piece is typically coated with a water-proofing and strengthening infiltrant like cyanoacrylate — otherwise known as super glue — or a different infiltrant, such as wax or epoxy. A second layer can also be added to improve the strength.

Binder jetting that uses plaster as its powder bed has relatively lower mechanical strength compared to other additive manufacturing processes and is mostly limited to nonfunctional applications such as prototyping.

Ayres and Sama examined plaster of Paris, a powder that fully or partially cures into gypsum when it interacts with a binder. Similar to a plaster cast, the powder particles are held together by the chemical change along with the bonding action provided by additional adhesives in the binder.

“The plaster parts are porous and have low mechanical strength, so they need to be infiltrated with a liquid that hardens to improve the structural strength to survive handling,” Ayres said. “Gypsum plaster is desirable in part for its ability to withstand high temperatures. We wanted to know what the best impregnation and infiltration methods were to take advantage of this.”

To conduct the research, Ayres printed the 3D parts out of his shop and shipped them via mail from Texas to State College. Sama tested the parts in various labs at the University Park campus, including the Mechanics and Materials Lab for mechanical testing and the Electroactive Materials Characterization Lab (EMCLab) for thermal testing.

“Sama did a great job of begging, borrowing and stealing time on a lot of the testing machines around campus,” Ayres said. “He did all sorts of testing, like compressive testing and thermal testing.”

Sama studied multiple methods of impregnating, or fully infiltrating, the plaster pieces with a strengthening coat of various epoxies.

Using statistical analysis to compare the data, Ayres and Sama found that vacuum impregnation resulted in the highest infiltration depth by fully impregnating the 25 mm cubic samples. This method seals the pores and possible leak paths in the print by filling the pores with a sealant while under pressure. In doing so, the sealant cures within the pores and creates a bond between the layers, increasing the print’s density.

Additionally, the best performing epoxy showed a 10% increase in mechanical strength, with a 76% reduction in cost.

Their work was published in the December 2019 issue of Additive Manufacturing.

“Tim was an excellent student with the maturity to understand that what we teach in the course is useful for both practice and research,” Joshi said. “The project was a perfect example of what we prepare students to do. Tim was able to use the design of experiments, material testing, the process knowledge and his knowledge to see what would benefit the binder jetting process users.”

Timothy W. Simpson, Paul Morrow Professor of Engineering Design and Manufacturing and director of the additive manufacturing and design program, shared similar sentiments.

“Tim is exactly the type of student we want in our online program,” Simpson said. “He has experience and a passion for 3D printing. He’s motivated to take full advantage of the multidisciplinary expertise of our faculty, as well as work with the resident students to get things done remotely. This is a win for everyone!”

For fun, for profit and for the future

Ayres, a mechanical engineering graduate from the University of Arizona, opened up a 3D printing shop in 2015 after he and his wife purchased a commercial two-floor, 100-year-old property in Arlington, Texas. Ayres and his wife live above their 3D printing shop, which used to serve as a framing gallery.

Ayres said that his business enables him to walk on the more artistic side of life.

“We can take scans of people and 3D print them in color,” Ayres said. “We like to go to museums and scan works of art. We can go to a museum, take a hundred pictures and then reconstruct it into a 3D model. We’ve made replicas for some of the local museums to hand out for tour groups or to enable people with disabilities to feel the museum pieces through 3D prints. It’s been inspiring because the jobs we get really span a wide variety of tasks.”

Ayres explained that the master’s program is helping him improve his business, as his work with Sama allowed him to apply the new ideas to his own prints. Ayres is now able to use the cost-saving epoxy in his personal projects, which enables him to save money over time while improving the strength and quality of his prints.

Ayres also believes that additive manufacturing is just at the beginning of the curve as technology continues to improve.

“Penn State is working on solving a lot of the additive manufacturing questions, especially with metal printing,” Ayres said. “You see a lot more custom things made inexpensively, so it’s going to open up a lot more markets. You won’t just have to settle for what’s on the shelf.”

The student spotlight series by the Penn State Harold and Inge Marcus Department of Industrial and Manufacturing Engineering (IME) aims to highlight innovators, makers and those that personify engineering excellence in their academic studies. The department currently has 90 doctoral students, 59 master’s students and 436 undergraduate students. In addition, the department hosts 31 full-time and courtesy faculty members. Established in 1908, the department is home to the first industrial engineering program in the world and has made a name for itself in the engineering industry through its storied tradition of unparalleled excellence and innovation in research, education and outreach. To learn more about IME and how you can get involved, visit


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Megan Lakatos

“I remember when I heard about the program and how it was one of the first of its kind in the country. It was definitely exciting.”
—Tim Ayres, online master’s degree student in additive manufacturing and design