When UVA engineering professor Mool Gupta saw the call for inventors to create a solar-powered, motorized wheelchair for the World Cerebral Palsy Day’s Change My World in One Minute campaign, he saw an opportunity for innovation.
Gupta, an expert in solar power, knew that previous attempts to craft a solar wheelchair had largely failed because they were inefficient, and had heavy, cumbersome solar panels that made it difficult for users to maneuver the chair.
“They were not very safe either, because the panels were made of glass that could shatter,” says Gupta.
So he gathered a team of four doctoral students and two undergraduates and set out to create a wheelchair that overcame those hurdles.
“A lot of our research is theory, not hands-on, so being able to build something that could be immediately put to use and help people was really what we wanted to do,” says Craig Ungaro, (Engr ’17) one of Gupta’s doctoral students.
After considering several ideas, they quickly settled on a design concept that mimics a convertible car, where overhead panels electronically retract behind the chair.
Gupta’s students scored a motorized wheelchair off Craigslist for $275, then set to work. They built custom solar panels that would be lighter than commercially available ones because they were smaller and used Plexiglas instead of glass. They bought a few hundred three-by-six-inch solar cells and soldered connections between the cells, overlaying them like shingles on Plexiglas; a hardening epoxy topped the panels.
But as the competition’s deadline was drawing near, the team encountered a few bumps.
A sticking retractable solar roof, for example, meant students had to rework the design so it would fold and unfold easily.
“To get [the panels] to slide properly, we ended up using drawer sliders, like in a desk drawer, and that ended up working,” Ungaro says.
Their final product can run for more than 4.5 hours at five miles per hour—full throttle for the motorized wheelchair—or indefinitely at low speeds.
It was innovative enough to win the grand prize of the competition.
The team plans to use part of the $20,000 prize money to ship its prototype wheelchair to a Turkish man who had submitted the competition idea to the World Cerebral Palsy Day panel. The rest of the prize money was returned to World Cerebral Palsy Day to support its mission, because, Gupta says, “That’s the right thing to do.”
Gupta has begun talks with nonprofits and foundations about creating a solar-powered component than can be added to any motorized wheelchair.
“We’ve got the concept, but that doesn’t take it to the people who really need solar-powered wheelchairs,” Gupta says. “Now the question is, ‘How do we [make] this idea available to the people who need it?’”