Swanson School, McGowan Institute Work to Advance 3D Printing Process

A mechanical part breaks on the International Space Station. No problem. An on-board 3D printer custom manufactures the part on demand.

An industrial accident shatters a construction worker’s femur. A CAT scan images the damaged bone, and a 3D printer uses that image to build a biodegradable “scaffold” to rebuild the bone and promote natural tissue growth during the healing process.

Research teams from the University of Pittsburgh’s Swanson School of Engineering and the Pitt-UPMC McGowan Institute for Regenerative Medicine are exploring ways to make those scenarios a reality through 3D printing. Also known as additive manufacturing, 3D printing is the process of making a three-dimensional solid object from a digital blueprint. The technology uses a robotic arm to lay successive layers of materials such as ceramics, metals, and polymers to create simple structures or complex parts.

Two Swanson research projects—one to manufacture lighter but stronger objects, and the second to make devices that help bodies heal—have received separate 18-month contracts totaling $1.5 million from America Makes, the National Additive Manufacturing Innovation Institute, based in Youngstown, Ohio, as well as Pitt and corporate partners. The proposals were two of 15 projects selected by America Makes as part of its second call for additive-manufacturing applied research and development projects.

The first contract comprises $438,000 from America Makes and a $526,000 match from Pitt and corporate partners. It will fund Swanson research aimed at integrating a cellular structure, or “latticework,” into the digital blueprint to make load-bearing products that weigh and cost less but still maintain the necessary structural integrity. Along with the Space Station example, another application would be manufacturing lighter parts for aircraft that would improve fuel efficiency without sacrificing reliability.

The first contract’s principal investigator is Albert To, a Pitt assistant professor of mechanical engineering and materials science. Co-principal investigators are Kevin P. Chen, a professor of electrical and computer engineering and Paul E. Lego Faculty Fellow, and David Schmidt, an assistant professor of mechanical engineering and materials science.

The Swanson School’s To aims to enhance the 3D printing process by integrating a computer-designed cellular structure into the layering process, allowing for more efficient and sustainable manufacturing.

“When we design a load-bearing structure, we need to span a certain volume. But we don’t need to create an entirely solid object; we just need to create a framework to maintain its structural integrity,” To explained. “By developing a computational model that allows us to integrate a cellular structure into the designs of [advanced manufactured] products, we can reduce weight, maintain load-bearing capacity, and enhance the sustainability of the entire process.”

Because advanced manufacturing is so new, To said, current computational tools don’t allow for the optimal design of a complex cellular structure within an advanced-manufactured product. He hopes to change that by coupling his research expertise in computational mechanics and materials with companies involved in additive manufacturing, computational modeling and materials. Corporate partners include Actuec Precision Machining Inc. (Saegertown, Pa.); Alcoa Inc. (Pittsburgh); ANSYS Inc. (Canonsburg, Pa.); and ExOne (North Huntingdon, Pa.).

The second project, valued at $590,000 from America Makes, includes researchers from both Swanson and the McGowan Institute for Regenerative Medicine.  Prashant Kumta, the Swanson School’s Edward R. Weidlein Chair Professor, is principal investigator. Kumta is also a professor of bioengineering, chemical and petroleum engineering, mechanical engineering and materials science, and a professor of oral biology in the School of Dental Medicine. Co-principal investigator is Howard Kuhn, an adjunct professor of industrial engineering. Patrick Cantini, director of scientific collaborations for UPMC and director of the McGowan Institute’s Center for Industry Relations, is serving as project manager.

Corporate partners include ExOne (North Huntingdon, Pa.), Magnesium Elektron (Madison, Ill.), and Hoeganaes Corp. (Cinnaminson, NJ).

“Additive manufacturing combines the best of technologies—the ability to construct complex structures via computer imaging using a combination of advanced biocompatible and, more importantly, biodegradable alloys,” Kumta said. “Thanks to computer-aided tomography, or CAT scans, we can directly image a damaged structure like a bone or trachea and construct a biodegradable iron-manganese-based scaffold to promote natural tissue growth during the healing process.”

In addition to precise modeling of a body structure, additive manufacturing allows for the use of biodegradable alloys that serve as functional scaffolds for inducing cell growth and for delivering biological molecules and antibiotics.

“Although we could create a ceramic or plastic part with additive manufacturing, this is not as ideal as an iron-manganese alloy, which is stronger, more ductile and degrades over time to be replaced by new bone,” Kuhn said.

“Additive manufacturing is a game-changer for biomedical research,” Kumta said. The process provides a framework structure for cells and tissue to grow, giving the body a better foundation to repair its own tissues. Additive manufacturing also can be used in remote areas such as army field hospitals, where access to traditional treatments may be limited.