Tandem wheelchair displays NIU engineering students' gritty innovation

The two wheelchairs that sit unassumingly inside one of Northern Illinois University's Engineering Building labs are testimony to one recent graduate’s persistence.

This summer, after more than two years of sustained effort, Noah Engles of the College of Engineering and Engineering Technology (CEET) achieved a proof-of-concept tandem wheelchair transportation device.

It was the latest milestone in a journey that began in early 2022, when Clare Kron, an instructor in NIU’s Department of Biological Sciences, met with the Biomedical Engineering Society, a CEET student group.

Kron had a vision for a front-and-back tandem wheelchair for her father-in-law, who was 91 at the time, and her mother-in-law, who was 87. Both had been active well into their retirement years and she wanted to enable continued mobility outdoors, while also enabling disconnection when one of them needed to go solo, such as using a bathroom.

Students enthusiastically took on the project; as Kron recalled, “They said this sounds exactly like what we’d want to do.”

At first, students aimed to wrap up the project by the end of spring semester 2022. But a series of technical questions and challenges arose:

How can we mount heavy-duty motors to drive two sitting patients simultaneously? How can we introduce connectivity hardware linking those two wheelchairs? How can we enable a singular driving caregiver to have dual-transportation capabilities?

In hindsight, those obstacles and delays are not so surprising—after all, as far as anyone involved in the project is aware, creating a tandem wheelchair is pioneering activity with none yet in the marketplace.

“I had to keep my word,” said Engles, who received a degree from NIU in biomedical engineering. “It felt fundamental for me as an individual, as a scientist, as a human being—I had to see it through.”

Along the way, Engles incorporated different elements such as trays that could be deployed to eat meals and umbrellas for protection from the sun.

“Noah added all these features that we worked on together that showed his concern about having a unit that is very user-friendly,” Kron said. “He always wanted to come through and do whatever would be best for humanity. It’s a beautiful unit. Maybe it can be a prototype that could be useful in a long-term nursing facility.”

However, because the effort is a proof-of-concept endeavor, it won’t move further toward deployment.

Now a biomedical engineering doctoral student at Washington University in St. Louis, Engles speaks with passion and joy about the experience, even as he acknowledges the effort took upwards of 12 hours a week of his time for the first two years.

The project tapped into his heart for older adults: Engles worked for two years as a cook at a senior care center and saw firsthand the challenges caregivers encounter in serving numerous residents in wheelchairs. He also recognizes the importance of getting outside and experiencing auditory and visual stimuli.

“The real motivation that got me into this was to stimulate older populations in those care facilities and keep them functioning at their highest peak,” Engles said.

One key step was outfitting the tandem wheelchairs with caster wheel modifications out front and two small motors in back. This enables maneuverability in every direction—and even a 360-degree spin—that is crucial for navigability. Engles said this “zero turn motion system” was a breakthrough concept in developing the tandem wheelchair, along with the telescoping capabilities of the connectivity hardware linking the chairs, one in front of the other.

The ability to innovate within subsystems was pivotal to Engles’ success, as was a comprehensive understanding of how those innovations affect the overall system’s behavior, then linking those behaviors to the unit’s performance.

“NIU provides a great opportunity through student groups,” he added. “It’s a chance for young minds and innovators to have an outlet for creating change. Groups like the Biomedical Engineering Society become a nice little home for projects like this to flourish.”

He was emphatic to note that others, including members of another student organization called Engineering World Health, made key contributions along the way. In all, Engles estimated there were 40 volunteers of varying lengths of time.

The project underscored interdependence’s role in the innovation process, whether it’s colleagues working side by side or turning to vendors for parts.

“Every person is unique and important to identify the optimal path and resolution,” Engles noted. “The biggest thing I learned is that the best path presents itself after everyone involved has a chance to contribute.”

CEET Dean Dave Grewell lauded the students’ effort, particularly the leadership that Engles provided.

“Noah has been so determined to get this done and it’s a credit to his self-motivation to bring the project to this stage,” Grewell said. “Part of the innovator’s journey is working through repeated failures and struggles. We’re all very proud of him and his peers who learned in this hands-on way.”

The NIU College of Engineering and Engineering Technology (CEET) provides affordable access to a world-class engineering education. Our fully accredited programs emphasize hands-on experience, with small classes taught by experienced, dedicated faculty that help a diverse array of students explore and ignite their passions in bachelor’s, master’s and doctoral degree programs. Learn more by visiting our website.