Michigan Technical Univ., www.mtu.edu

Seniors in mechanical engineering at Michigan Technological Univ. designed and built a hand-powered wheelchair that can travel unpaved nature trails and paths. Those using the 55-lb chair “row” or pull on a pair of articulated arms to power the device through eight-speed dual-bicycle-type gears, one on each side of the chair. Top speed is about 4 mph and it can scale a 28° slope. The students kept the chair’s center of gravity low so it would be stable and easy to maneuver. It’s turning radius is the same as a standard wheel chair despite its longer wheelbase. For safety, students installed one-way bearings in the main wheels for zero rollback on inclines. The handlebars also swing out of the way to make it easy to get in and out of the chair.

The chair, which was built using a $3,000 budget, will be used by disabled students on paths through the University’s on-campus forest and recreation area.