Disabled people in the developing world often have to drag themselves down the street to get anywhere,” says Harry O’Hanley, adding that 20 million of these people need a wheelchair, but only 1 to 5 percent actually own one.

“I love to build things and wanted to contribute something tangible to the world,” says O’Hanley, who when he arrived as a freshman, immediately signed up for one of MIT’s 50 service learning classes. The class, Wheelchair Design in Developing Countries, inspired him so much that he is still working two years later to refine a wheelchair that can go long distances, uphill, over dirt roads and rough terrain, and is compact enough to be used indoors.

“I loved building this object that will help others,” he says.

O’Hanley, a junior who studies mechanical engineering, worked with his team to design a chair with two big tires in the back and a small one in front. Two levers extend from the knee area. Pushing one lever allows you to move the chair forward, and sliding your hands up both levers enables you to climb uphill.

“It’s essentially having a gear system in your wheelchair. When you put your hands up high on the levers you have a huge amount of torque. You can go uphill over almost any terrain,” he says.

Last year, O’Hanley traveled to Nairobi, where he designed and distributed eight wheelchairs to the disabled in Tanzania, Kenya, and Uganda. “We designed the chair with bicycle parts; so if it breaks, a local bike technician can fix it.” Their goal, he says, is to produce and distribute 100 chairs by next summer.

“I met a guy in Nairobi who went 138 kilometers in a wheelchair and rode with a flat tire for four days to get it fixed,” he says. “Now, people have more mobility. They can go a few kilometers and not be out of breath. They can go outside their village to school or work, and it really changes their lives.”

O’Hanley says his work in Nairobi opened his eyes to other engineering problems there — “They need power in the villages and access to clean water. I want to continue to apply my engineering skills to serve others.

“I loved seeing the people’s faces after we gave them the wheelchair and watched them zip around and go uphill. It was so cool. After you work on a service project, it’s hard to find gratification working on a project that does not directly benefit someone else.”